outlier (n.)

c. 1600, "stone quarried and removed but left unused," from out- + agent noun from lie (v.2). Transferred meaning "outsider" (in reference to persons) is recorded from 1680s, especially "one who does not reside in the place of his office or duties;" the sense of "anything detached from its main body" is from 1849; the geological sense is from 1833.