Godan verb with 'mu' ending, Intransitive verb
to draw back; to sink; to cave in
今までどこに引っこんでいたのですか。Where've you been keeping yourself? to be set back (e.g. from a road)
to withdraw (e.g. from the public eye); to retire to (somewhere); to stay indoors; to butt out; to stay out of it
Also written 引っこむ【ひっこむ】