"distant in relationship" (by some expressed degree, for example first cousin once removed), 1540s, from past participle of remove (v.). Meaning "remote, separated, secluded" from something is from 1610s.
Entries linking to removed
remove v.
early 14c., remouven, remuvien, remēven, "take (something) away; dismiss" from an office, post or situation; from Old French removoir "move, stir; leave, depart; take away," from Latin removere "move back or away, take away, put out of view, subtract," from re- "back, away" (see re-) + movere "to move" (from PIE root *meue- "to push away").
Sense of "go away, leave, depart, move" from a position occupied is from late 14c.; the intransitive sense of "change (one's) place, move from one place to another" also is from 14c. Related: Removed; removing.