无力
wúlì · HSK 7
lack strength
🪫 无力 = 无 (without) + 力 (strength) — literally without-strength, powerless
无 means none or without; 力 means strength or force (a 力 alone is the character for power). Stack them and you get without-strength: drained, weak, unable to act. The same 力 shows up in 力气 (physical strength) and 努力 (to exert effort).
无 — top 一 + 林-like middle + fire radical 灬 below
Originally a pictograph of a person dancing while holding ornaments or tassels, meaning 'to dance' — the ancestor of 舞. It was borrowed phonetically to write the negative 'not have / without,' and the dance meaning was reassigned to 舞 with an added foot element. The simplified form 无 comes from an ancient variant.
力 — pictograph of a plow or arm muscle
力 originated as a pictograph of an ancient plow, the main tool requiring physical exertion in early agriculture. Some scholars also see it as a flexed arm showing muscle. From this concrete image it broadened to mean 'strength, power, force, effort'.