adverb, verb · to permit or give authorization for something

这里不许抽烟。

verb · to pledge, vow, or commit to something

我许他三天之后一定把钱还清。

verb · to express a desire or hope, specifically used in the context of making a wish.

我许下了一个愿望。

verb · to commend, approve, or speak highly of

他那过人的胆识，深得当时的英雄豪杰所许。

numeral · to a certain degree, a little bit, or approximately

我家离学校不过两里许，走着去很快就到了。

proper name · surname Xu

他姓许。

adverb · indicating a possibility or uncertainty; maybe

许是他最近工作太累，竟然在开会时睡着了。