Languages have morphemes that elude the well‐known distinctions between the morphological categories ‘affix’ and ‘clitic’. These unusual morphemes are affix‐like in that they preserve the property of selecting lexemes as bases, but they are clitic‐like as they can also attach to phrases, thus have bases that are formed in syntax. Some of these morphemes are also displaced and appear on items that they are not associated with. This entry surveys the emergence and development of the term ‘phrasal affix’, used for referring to such morphemes, and its appearance in the inflectional and derivational domains in various languages across different language families. It focuses on works that have analysed phrasal affixation within various theoretical frameworks and discusses the categories of the phrases that such affixes take as bases.