n.

1. 变音；转调
2. 弯曲；向内弯曲
3. 【语】屈折变化；屈折形式

n.

1. Grammar  a change in the form of a word (typically the ending) to express a grammatical function or attribute such as tense, mood, person, number, case, and gender.
2. the modulation of intonation or pitch.
3. chiefly Mathematics  a change of curvature from convex to concave.