明喻是用在直接比较两个基本上不相同或有关的事物，并用「像」等作为连接词，为一修辞手法。通常，一个第一个事物的外形、特性等会和第二个物体相似。

明喻的结构主要分为三部份：喻体，指作者欲描述之主题；喻依，指的是用来说明喻体的事物；喻词，指用来链接喻体和喻依的补助词。

这句鲁迅于《华盖集·杂感》中的句子便是一个例子。句中，时间被直接地和海绵里的水作比较，其目的是用「海绵里的水」的意义来比较「时间」，表达出「只要愿挤，总是还是有的」的意思。而例中，「时间」是喻体、「海绵里的水」是喻依，「像」则是喻词。

A simile (/ˈsɪməli/) is a figure of speech that directly compares two things. Although similes and metaphors are similar, similes explicitly use connecting words (such as like, as, so, than, or various verbs such as resemble), though these specific words are not always necessary. While similes are mainly used in forms of poetry that compare the inanimate and the living, there are also terms in which similes and personifications are used for humorous purposes and comparison.