嘘と坊主の頭はゆったことがない
Meanings
1
having never told a lie
jocular, humorous
A jocular set phrase playing on the homophony of 言う (to say) and 結う (to tie up, do up hair). Literally 'a lie and a monk's head have never been tied up', meaning 'I have never told a lie' because a monk's bald head cannot be tied up, just as a lie cannot be 'tied' (said). Used humorously to claim one has never lied.
My old man used to say, 'I've never told a lie,' with that pun about a monk's head.