How's that for a boring blog title?
Seriously though, one of the reasons that I tend to be such strong advocate for an omniglot approach or at least attempting to have a basic understanding of terms in other languages that relate to our practices is that often there are nuances within those terms that are - quite literally - lost in translation. And we shape our understanding, our conceptualization, of things based on our own reference language. In psychology this is called the Sapir-Whorf hypothesis and it says that language shapes our thoughts and behaviors in line with the culture of that language.
To give you an example, in English when we think about colors we think of shades on a spectrum of light, so that 'red' is certain frequency usually appearing as a fairly standard red which we then modify with words like 'light' or 'dark' (I'm speaking generally here of course). In Irish on the other hand color is not an abstract concept but a concrete one referring to actual physical colors and this gives us multiple words translated as the same color which aren't actually the same. Uaine is green but its a vivid, bright green, while glas is also green but can be a grey-green or sea green. Dearg is red, but so is rua; dearg being bright rua being more a natural hue. And in old Irish there are an array of words for red that all refer to different shades of blood or states of blood. My point here is that the languages themselves have different ways of understanding something as basic as the concept of colors.
In English we have the word witch and it gets a lot of play in modern paganism. And I do mean a lot. When you read translations of Irish myths and texts you'll run across witches and references to witchcraft but here's where the language issue comes in because what is being translated as 'witchcraft' in English may have been one of at least 8 different words in Sengoidelc: ammaitecht, diabultacht, dolbud, gliccus, pisoca, sidaigecht, tuaichlecht, tuaithe. Each of these has distinct nuances and undertones that are important in context. I'm going to take a look at each term one by one so you can see what I mean. I'm also going to offer some modern equivalents, or at least my opinion on what modern equivalents might be, to help clarify.
~ Ammaitecht - defined by the eDIL as "a. profession or activity of an ammait, witchcraft, evil influence; b. foolishness". An ammait is defined as "a woman with supernatural powers, a witch, hag, spectre; a Fury" and also "a foolish woman". Interestingly however an ammait is also equated with a bandrui or female druid, meaning the two terms were seen as the same. This might explain why ammait and ammaitecht are also connected to foolishness as after the conversion period the Druids lost much status and were reduced in the law texts to the equals of fools*. So ammait and ammaitecht are associated with female Druids, and ammaitecht is seen as a profession.
~ Diabultacht - defined as "witchcraft, enchantment" this is pretty obviously based off the Latin loan word Diabul (Latin - diabolus) meaning the Devil. Indeed in the eDIL this type of magic is described as 'melancholia' or deep sadness. This is the sort of witchcraft that is classically associated with witches in a Christian framework, who sell their souls to the Devil and cause misery in other people. A more accurate definition from a pagan perspective might be diabolism,
~ Dolbud - defined as witchcraft or sorcery, the word also means "invention, formation, the act of forming". The example sentences used in the eDIL come from the Gaelic Journal: Irisleabhar na Gaedhilge and associate this type of witchcraft with the magic of forming geasa, or ritual taboos. This type of witchcraft then is focused on manifestation.
~ Gliccus - defined as witchcraft or sorcery, gliccus also means cleverness, skill, and ingenuity.
~ Pisoca - also piseoga, defined as witchcraft, sorcery, or magic, specifically the use of charms and spells. Bean phiseogach is translated as witch in English but clearly has the implication of a woman who uses charms and spells in particular. Probably closest to what modern pagans understand a witch to be.
~ Sidaigecht - defined as witchcraft or magic. However this one is clearly more complex than just that definition. The base word "sidaig" refers to a dweller in a fairy hill, or in other words a fairy so this is rather particularly the magic of the sidhe. One might refer to this as fairy magic for better accuracy rather than witchcraft as we understand it.
~ Tuaichlecht - defined as "cunning, witchcraft" tuaichlecht is derived from the word for cunning 'tuaichles' and we see it in examples like "le draidhecht ocus tuaichlecht" (of magic and witchcraft). A better translation for this one based on a modern pagan understanding might be "cunningcraft" in the sense of the art of the cunningman or woman.
~ Tuaithe - defined as witchcraft or sorcery and related to the word tuath, meaning "northward, turning nothward, perverse, wicked". Tuaithe is a complex word that is associated with both the Good Folk (tuath-geinte) as well as witches (tuaithech or bantuaithech), and to make things more complex although the word tuath has strong negative associations bantuaithech is also defined as 'wise woman' and tuaithech by itself only means "a person with magic powers". We might tentatively conclude then that this particular type of witchcraft is associated with the Otherworld and can be sinister in nature or benevolent, rather like the sidhe themselves*.
Looking at words for witch we have:
ammait or benammait - both are feminine and as discussed above besides meaning witch are also equated to a female Druid.
badb - female only, originally the name of a War Goddess, later used for spectres, and eventually for human witches.
ban-cumachtach - female, literally 'woman with magical powers'
ban-cumachtach sithe - female - 'fairy witch'
bean phiseogach - female, witch
cailleach - female, hag, witch, crone
cumachtach sithe - male, fairy witch
doilbhtheach - male, "person with magical powers", practitioner of dolbud, witchcraft of manifestation (usually translated as sorcerer*)
lucht piseog - 'sorcerers' but more literally 'people of witchcraft'
tuathaid/tuaithech - male, person with supernatural power, witch ~ bantuathaid/bantuaithech - female, same as tuaithech, also defined as 'wise woman'
*We see a similar pattern of reducing the power of a term and its associated being with the word "Badb" which was the name of a Goddess and later became a word for a human witch. See Fergus Kelly's Guide To Early Irish Law for a more detailed discussion of the legal position of Druids in the law texts and of women who practiced magic.
*Tuaithe is the witchcraft that I practice so I may be a bit biased in how I perceive its definition.
* in several cases the exact same thing being practiced by a woman will have her being called a witch in translation, but a man will be called a sorcerer, as we see with bean phiseogach and lucht piseogach. The only change between the terms is the gender of the practitioner(s).