a word or phrase with the symbol ‘#’ in front of it, used on social media websites and apps so that you can search for all messages with the same subject 主题标签，话题标记，题标（推特消息中将 # 号置于某些词语前，方便用户搜索同一主题的所有消息） I often use hashtags to search for trending topics. 我经常用主题标签搜索热门话题。
- (British English also hash, hash sign)(North American English also pound sign)
the symbol ( # ), especially one on a phone or computer keyboard （尤指电话上的）# 号