多式综合语（polysynthetic language又称编插语、相抱语、复综语）是综合语的一种，拥有极高的综合语特性。多式综合语的词，都由许多的词素组成。

如果以「综合程度」指词素和词之间的比例，当某种语言的词由多于一个词素组成，这种语言便称为综合语。以综合程度而言，多式综合语走在「每个词都由极多的词素组成」的极端。（在另一个极端，就是一个词只由一个词素组成的孤立语。）

这些综合程度极高的语言一般通有非常长的词。在综合程度较低的语言，通常需要整句才能表达这些词的意义。

并入 (主要是名词并入) 是多式综合语有史以来一个令人混淆的特征, 而此亦因而用来定义多式综合语。「并入」是指词素 (Lexical morphemes 或称词汇单位 Lexemes) 全都结合成一个单字的现象。可是有的并入语不是多式综合语, 反之亦然。

In linguistic typology, polysynthetic languages are highly synthetic languages, i.e. languages in which words are composed of many morphemes (word parts that have independent meaning but may or may not be able to stand alone). Polysynthetic languages typically have long "sentence-words" such as the Yupik word tuntussuqatarniksaitengqiggtuq which means "He had not yet said again that he was going to hunt reindeer." The word consists of the morphemes tuntu-ssur-qatar-ni-ksaite-ngqiggte-uq with the meanings, reindeer-hunt-future-say-negation-again-third.person.singular.indicative; and except for the morpheme tuntu "reindeer", none of the other morphemes can appear in isolation.