無能
むのう · munou · JLPT N1 · noun
incompetence
無 (none) + 能 (ability) = no ability, the opposite of 有能 (capable)
無 negates the kanji after it, as in 無料 (no fee) and 無理 (no reason). So 無能 literally means lacking ability. The 能 here is read のう in this compound.
能 — 厶 (head) + 月 (body/flesh) + 匕匕 (legs)
Originally a pictograph of a bear, showing its head, body, and powerful legs. Because bears were seen as strong and capable, the character was borrowed to mean 'ability' or 'can'. A new character 熊 (with the fire radical 灬) was later created for 'bear'.