Further to Caoimhin & Bill's comments on "Buachaill/Buachaille", it's also
related to the word "bucolic" (rustic, pastoral if you're not familiar with it)
since this English word derives from Greek via Latin'boukolikos', a herdsman.
Interesting to see such continuity in Scottish Gaelic without developing the
more generalised Irish meaning, although of course there is the secondary usage
in a religious context to mean 'shepherd' - "'Se Dia fein as Buachaill dhomh" -
the Lord is my Shepherd (not ciobair or giobair).