inquiline (n.)

1640s, "a lodger," from Latin inquilinus "an inhabitant of a place not his own," from *incolinus, from incola "an inhabitant," from in- "in" (from PIE root *en "in") + colere "inhabit, dwell" (see colony). Zoological sense of "animal living in the abode of another, a commensal" is from 1865.