variation; variant form
Refers to a different form or pattern of something, often used in linguistic, grammatical, or technical contexts.
この単語にはいくつかの変化形がある。
This word has several variant forms.
動詞の変化形を覚えるのは大変だ。
Memorizing verb conjugations is tough.
Compound of 変化 (henka, 'change') + 形 (kei, 'form').