Origin: 1815–25; < L retrōrsus, contracted form of retrōversus bent backward, equiv. to retrō-retro-+ versus (ptp. of vertere to turn); see retroversion
re·trorse (rĭ-trôrs', rē'trôrs') adj. Directed or turned backward or downward.
[Latin retrōrsus, from retrōversus : retrō-, retro- + versus, past participle of vertere, to turn; see wer-2 in Indo-European roots.] re·trorse'ly adv.