Technical term used in grammar, programming, and other fields for an element that modifies or qualifies another.
In this programming language, you can restrict the access scope of variables using modifiers.
In Japanese grammar, words that modify nouns are sometimes called modifiers.
Compound of 修飾 (modification) and 子 (a suffix used for small or subordinate elements, here meaning 'element'). The exact derivation is uncertain, but the term is a modern technical coinage.