noun, na-adjective
talentless and incompetent; unaccomplished
A self-deprecating or critical description of someone lacking any particular skill or achievement. Often used in humble expressions about oneself.
私は無芸無能の人間です。
I am a person with no special talents or abilities.
彼は無芸無能な社員だと思われている。
He is thought of as an incompetent and unaccomplished employee.
無芸 means 'having no artistic skill or talent' and is less common alone; 無芸無能 combines it with 無能 for a stronger, more comprehensive expression of uselessness.
A yojijukugo (four-character compound) combining 無 (without), 芸 (art, skill), 無 (without), and 能 (ability). The exact origin is uncertain, but it follows a common pattern of negating two related qualities to emphasize complete lack.