. [ L. retro, adv., backward, back. Cf. Re-. ] A prefix or combining form signifying backward, back; as, retroact, to act backward; retrospect, a looking back. [ 1913 Webster ]

v. i. [ Pref. retro- + act. ] To act backward, or in return; to act in opposition; to be retrospective. [ 1913 Webster ]

n. [ Cf. F. rétroaction. ] 1. Action returned, or action backward. [ 1913 Webster ]

2. Operation on something past or preceding. [ 1913 Webster ]

a. [ Cf. F. rétroactif. ] Fitted or designed to retroact; operating by returned action; affecting what is past; retrospective. Beddoes. [ 1913 Webster ]

Retroactive law or
Retroactive statute (Law), one which operates to make criminal or punishable, or in any way expressly to affect, acts done prior to the passing of the law. [ 1913 Webster ]

adv. In a retroactive manner. [ 1913 Webster ]

v. t. [ Pref. retro- + cede: cf. F. rétrocéder. ] To cede or grant back; as, to retrocede a territory to a former proprietor. [ 1913 Webster ]

v. i. [ L. retrocedere; retro backward, back + cedere to go. See Cede. ] To go back. [ 1913 Webster ]

a. [ L. retrocedens, p. pr. ] Disposed or likely to retrocede; -- said of diseases which go from one part of the body to another, as the gout. [ 1913 Webster ]

n. [ Cf. F. rétrocession. See Retrocede. ] 1. The act of retroceding. [ 1913 Webster ]

2. The state of being retroceded, or granted back. [ 1913 Webster ]

3. (Med.) Metastasis of an eruption or a tumor from the surface to the interior of the body. [ 1913 Webster ]

n. [ Pref. retro- + choir. ] (Eccl. Arch.) Any extension of a church behind the high altar, as a chapel; also, in an apsidal church, all the space beyond the line of the back or eastern face of the altar. [ 1913 Webster ]

a. [ See Retrocopulation. ] Copulating backward, or from behind. [ 1913 Webster ]

n. [ Pref. retro- + copulation. ] Copulation from behind. Sir T. Browne. [ 1913 Webster ]

n. [ L. retroducere, retroductum, to lead or bring back; retro backward + ducere to lead. ] A leading or bringing back. [ 1913 Webster ]

{ } a. [ Pref. retro- + L. flectere, flexum, to bend, to turn. ] Reflexed; bent or turned abruptly backward. [ 1913 Webster ]

n. The act of reflexing; the state of being retroflexed. Cf. Retroversion. [ 1913 Webster ]

{ } a. [ Pref. retro- + L. fractus, p. p. of frangere to break. ] (Bot.) Refracted; as, a retrofract stem. [ 1913 Webster ]

a. [ Pref. retro- + generative. ] Begetting young by retrocopulation. [ 1913 Webster ]

n. [ F. rétrogradation or L. retrogradatio. See Retrograde. ] 1. The act of retrograding, or moving backward. [ 1913 Webster ]

2. The state of being retrograde; decline. [ 1913 Webster ]

a. [ L. retrogradus, from retrogradi, retrogressus, to retrograde; retro back + gradi to step: cf. F. rétrograde. See Grade. ] 1. (Astron.) Apparently moving backward, and contrary to the succession of the signs, that is, from east to west, as a planet. Hutton. [ 1913 Webster ]

And if he be in the west side in that condition, then is he retrograde. Chaucer. [ 1913 Webster ]

2. Tending or moving backward; having a backward course; contrary; as, a retrograde motion; -- opposed to progressive. “Progressive and not retrograde.” Bacon. [ 1913 Webster ]

It is most retrograde to our desire. Shak. [ 1913 Webster ]

3. Declining from a better to a worse state; as, a retrograde people; retrograde ideas, morals, etc. Bacon. [ 1913 Webster ]

v. i. [ imp. & p. p. Retrograded p. pr. & vb. n. Retrograding. ] [ L. retrogradare, retrogradi: cf. F. rétrograder. ] 1. To go in a retrograde direction; to move, or appear to move, backward, as a planet. [ 1913 Webster ]

2. Hence, to decline from a better to a worse condition, as in morals or intelligence. [ 1913 Webster ]

adv. By retrograding; so as to retrograde. [ 1913 Webster ]

n. [ Cf. L. retrogressus. ] Retrogression. [ R. ] H. Spenser. [ 1913 Webster ]

n. [ Cf. F. rétrogression. See Retrograde, and cf. Digression. ] 1. The act of retrograding, or going backward; retrogradation. [ 1913 Webster ]

2. (Biol.) Backward development; a passing from a higher to a lower state of organization or structure, as when an animal, approaching maturity, becomes less highly organized than would be expected from its earlier stages or known relationship. Called also retrograde development, and regressive metamorphism. [ 1913 Webster ]

a. [ Cf. F. rétrogressif. ] 1. Tending to retrograde; going or moving backward; declining from a better to a worse state. [ 1913 Webster ]

2. (Biol.) Passing from a higher to a lower condition; declining from a more perfect state of organization; regressive. [ 1913 Webster ]

adv. In a retrogressive manner. [ 1913 Webster ]

n. The quality or state of being retromingent. Sir T. Browne. [ 1913 Webster ]

a. [ Pref. retro- + L. mingens, p. pr. of mingere to urinate. ] Organized so as to discharge the urine backward. -- n. (Zool.) An animal that discharges its urine backward. [ 1913 Webster ]

a. [ Pref. retro- + L. pellere, pulsum, to impel. ] Driving back; repelling. [ 1913 Webster ]

a. [ L. retrorsus, retroversus; retro back + vertere, versum, to turn. Cf. Retrovert. ] Bent backward or downward. -- Re*trorse"ly, adv. [1913 Webster]

v. i. [ L. retrospicere; retro back + specere, spectum, to look. See Spy, and cf. Expect. ] To look backward; hence, to affect or concern what is past. [ 1913 Webster ]

It may be useful to retrospect to an early period. A. Hamilton. [ 1913 Webster ]

n. A looking back on things past; view or contemplation of the past. Cowper. [ 1913 Webster ]

We may introduce a song without retrospect to the old comedy. Landor. [ 1913 Webster ]

n. The act, or the faculty, of looking back on things past. [ 1913 Webster ]

a. [ Cf. F. rétrospectif. ] 1. Looking backward; contemplating things past; -- opposed to prospective; as, a retrospective view. [ 1913 Webster ]

The sage, with retrospective eye. Pope. [ 1913 Webster ]

2. Having reference to what is past; affecting things past; retroactive; as, a retrospective law. [ 1913 Webster ]

Inflicting death by a retrospective enactment. Macaulay. [ 1913 Webster ]

adv. By way of retrospect. [ 1913 Webster ]

n. (Med.) The inoculation of a cow with human vaccine virus. [ 1913 Webster ]

n. [ Cf. F. rétroversion. See Retrovert. ] A turning or bending backward; also, the state of being turned or bent backward; displacement backwards; as, retroversion of the uterus. [ 1913 Webster ]

☞ In retroversion the bending is gradual or curved; in retroflexion it is abrupt or angular. [ 1913 Webster ]

v. t. [ imp. & p. p. Retroverted; p. pr. & vb. n. Retroverting. ] [ Pref. retro- + L. vertere, versum, to turn. Cf. Retrorse. ] To turn back. [ 1913 Webster ]

a. In a state of retroversion. [ 1913 Webster ]