boner
noun [ C ] uk/ˈbəʊ.nər/ us/ˈboʊ.nɚ/
(PENIS)
mainly US offensive(阴茎的)勃起
an erection (= an occasion when a man's penis is hard)
(MISTAKE)
US informal愚蠢可笑的错误
a mistake that causes embarrassment to the person who makes it