(bound form) base; foundation / (bound form) radical (chemistry) / (bound form) gay (loanword from English into Cantonese, Jyutping: gei1, followed by orthographic borrowing from Cantonese)
used in expressions that convey frustration and futility, such as 無奈|无奈[wu2 nai4] and 莫可奈何|莫可奈何[mo4 ke3 nai4 he2] (literary) / used for its phonetic value in writing foreign words