inquiline
Concise Oxford English Dictionary © 2008 Oxford University Press:
inquiline /ˈɪnkwɪlʌɪn, -liːn/
▶noun Zoology an animal exploiting the living space of another, e.g. an insect that lays its eggs in a gall.
– origin C17: from L. inquilinus ‘lodger’, from in- + colere ‘dwell’.
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