numeral, verb, adverb, modal particle, adjective, punctuation, noun · placed after a number and measure word to indicate an additional half unit

已经过去一个半小时了。

numeral, punctuation · one of two equal parts of a whole

请给我半个西瓜。

measure word, adjective, numeral · partial, to some degree, or halfway

这种材料是半透明的。