Daniel Cassidy, in his absurd and ridiculous work of pseudo-scholarship, How The Irish Invented Slang, claimed that the word boot (as in ‘to boot’) comes from the Irish word babhta.
In fact, the etymology of the words boot and bout in English is quite complex.
Boot comes from the Old English bot ‘help, relief, advantage; atonement,’ while bout comes from a Middle English word bught meaning ‘a bend’. Neither of these words has any connection with boot meaning shoe (which is from French) and only a distant connection with booty meaning captured prize, which is from Germanic through French (and acquired its current meaning as in ‘bootilicious’ through Black American English). Freebooter is from Dutch.
At some stage over the last four hundred years, the English word bout was borrowed into Irish as babhta. There is no doubt that this is a borrowing into Irish and not the other way round. As we have said before, the only words with this pattern of sounds in Irish are borrowings, words like stabht (the drink, stout), clabhta (clout), dabht (doubt) or fabht (fault). In Irish, the meanings of the two English words boot and bout are conflated in babht, because we find expressions like de bhabhta, to boot, as well as babhta tinnis, a bout of illness.