There are several such words in
Cantonese that for a long time, my friends and I could not satisfactorily translate into English.
無聊
(mo liu) - this partially means '
inane', but the English word doesn't give the full meaning.
無奈
(mo noi) - best expressed by
-_- or perhaps
^_^;. The usual English term 'to
sweat-drop' is gacked from Japanese anime where characters do this when they are mo noi, usually accompanied by a blue/black cloud around their head plus a drop of sweat/several straight lines.