势 is a bound morpheme (b.f.) that never appears alone — it must combine with another character to form a word. Its most common compounds include 势力 (power/influence), 局势/形势 (situation/circumstances), 手势/姿势 (gesture/posture), and 趋势 (trend). A rare classical sense refers to male genitalia, but learners typically encounter it in the modern, political or postural meanings.