Godan verb with 'mu' ending, Transitive verb
to wear (multiple layers of clothes); to wear underneath; to bundle up; to dress warmly
別に制服着込んだ外宇宙の使者が、伴侶を求めて徘徊してるわけでもなかろうに。It's not as if an emissary from outer space will have slipped into uniform and be loitering around seeking a partner. to dress up (esp. in formal clothes); to attire oneself (in); to put on (e.g. a dress)
to break in (through repeated wearing); to wear in
esp. in fashion
Also written 着籠む【きこむ】