I looked at Chipp and Fiffle. "Nanohedron" asked about "crannciuil". I'm not familiar with the term but "crann" is usually a tree, a beam or a mast. "ciùil" is the genitive in Scottish Gaelic of the word "ceòl", (of) music. That form of the genitive appears to have been used in places in Ireland in the past; it is given as an alternative in Dineen's 1904 dictionary. But I don't know whether or not "crannciùil" would be used to describe a hornpipe, as Nanohedron suggests. There certainly is an association between the word "crann" and sailing. I can't find "crannciùil" in Dwelly's dictionary, but interestingly, there is a word "crann-dòrdain" = "sort of music produced by applying the hand to the mouth".

I think the ornamentation called "cranning" does come from the word "crann" , as the Irish Gaelic word "crannáil" can refer to latticework!

Nanohedron also asked about "Seisd", (or séist) which is also Scottish Gaelic and means a chorus or refrain ("curfá" or "loinneóg" in Irish). The word séist can also be used more generally to refer to a melody. I am not aware of séist being used in this sense in Irish, but there is a term "séis cheoil" = a strain of music.