間抜け also means 'fool' or 'blockhead', but often emphasizes stupidity or slowness, whereas 抜け作 highlights a lack of attention or a blunder.
Etymology
Derived from the verb 抜ける (nukeru, 'to come out, to be missing') and 作 (saku, a common suffix in names and derogatory terms). The combination suggests someone who is 'missing' something, i.e., lacking intelligence or common sense.
