Merriam-Webster Collegiate Dictionary - extrinsic factor

 noun  Date: 1938 vitamin B12 EXTRINSIC  adjective  Etymology: French & Late Latin; French extrinseque, from Late Latin extrinsecus, from Latin, adverb, from without; akin to Latin exter outward and to Latin sequi to follow — more at exterior, sue  Date: 1613  1.  a. not forming part of or belonging to a thing ; extraneous  b. originating from or on the outside; especially originating outside a part and acting upon the part as a whole ~ muscles of the tongue  2. external  • ~ally adverb Synonyms:  ~, extraneous, foreign, alien mean external to a thing, its essential nature, or its original character. ~ applies to what is distinctly outside the thing in question or is not contained in or derived from its essential nature sentimental value that is ~ to the house's market value. extraneous applies to what is on or comes from the outside and may or may not be capable of becoming an essential part arguments extraneous to the issue. foreign applies to what is so different as to be rejected or repelled or to be incapable of becoming assimilated techniques foreign to French cuisine. alien is stronger than foreign in suggesting opposition, repugnance, or irreconcilability a practice totally alien to her nature.