体力
tǐlì · HSK 5
strength
💪 体 (body) + 力 (strength) = body-strength, i.e. stamina
体 means body and 力 means strength or force. Together 体力 is literally body-strength — the physical energy or stamina you have for exertion, not abstract willpower.
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'.