Backside and Reverse

backside

The side of an object that is opposite its front.
- usage: "his room was toward the rear of the hotel"
- synonyms: rear, back end
The fleshy part of the human body that you sit on.
- usage: "he deserves a good kick in the butt"; "are you going to sit on your fanny and do nothing"
- synonyms: buttocks, nates, arse, butt, bum, buns, can, fundament, hindquarters, hind end, keister, posterior, prat, rear, rear end, rump, stern, seat, tail, tail end, tooshie, tush, bottom, behind, derriere, fanny, ass

(n.) The hinder part, posteriors or rump of a person or animal.

Webster's Revised Unabridged Dictionary

reverse

A relation of direct opposition.
- usage: "we thought Sue was older than Bill but just the reverse was true"
- synonyms: contrary, opposite
The gears by which the motion of a machine can be reversed.
- synonyms: reverse gear
An unfortunate happening that hinders or impedes; something that is thwarting or frustrating.
- synonyms: reversal, setback, blow, black eye
The side of a coin or medal that does not bear the principal design.
- synonyms: verso
American football. ( a running play in which a back running in one direction hands the ball to a back running in the opposite direction)
Turning in the opposite direction.
- synonyms: reversion, reversal, turnabout, turnaround

Change to the contrary.
- usage: "The trend was reversed"; "the tides turned against him"; "public opinion turned when it was revealed that the president had an affair with a White House intern"
- synonyms: change by reversal, turn
Turn inside out or upside down.
- synonyms: turn back, invert
Rule against.
- usage: "The Republicans were overruled when the House voted on the bill"
- synonyms: overrule, overturn, override, overthrow
Cancel officially.
- usage: "He revoked the ban on smoking"; "lift an embargo"; "vacate a death sentence"
- synonyms: revoke, annul, lift, countermand, repeal, overturn, rescind, vacate
Reverse the position, order, relation, or condition of.
- usage: "when forming a question, invert the subject and the verb"
- synonyms: invert

Directed or moving toward the rear.
- usage: "a rearward glance"; "a rearward movement"
- synonyms: rearward
Of the transmission gear causing backward movement in a motor vehicle.
- usage: "in reverse gear"
Reversed (turned backward) in order or nature or effect.
- synonyms: inverse

(a.) Hence, to overthrow; to subvert.
(a.) That which appears or is presented when anything, as a lance, a line, a course of conduct, etc., is reverted or turned contrary to its natural direction.
(a.) To turn back; to cause to face in a contrary direction; to cause to depart.
(a.) The act of reversing; complete change; reversal; hence, total change in circumstances or character; especially, a change from better to worse; misfortune; a check or defeat; as, the enemy met with a reverse.
(a.) That which is directly opposite or contrary to something else; a contrary; an opposite.
(a.) The back side; as, the reverse of a drum or trench; the reverse of a medal or coin, that is, the side opposite to the obverse. See Obverse.
(a.) To overthrow by a contrary decision; to make void; to under or annual for error; as, to reverse a judgment, sentence or decree.
(a.) To change totally; to alter to the opposite.
(a.) Reversed; as, a reverse shell.
(v.i.) To return; to revert.
(a.) To turn upside down; to invert.
(a.) To cause to return; to recall.
(v.i.) To become or be reversed.
(a.) A thrust in fencing made with a backward turn of the hand; a backhanded stroke.
(a.) Turned upside down; greatly disturbed.
(a.) A turn or fold made in bandaging, by which the direction of the bandage is changed.
(a.) Turned backward; having a contrary or opposite direction; hence; opposite or contrary in kind; as, the reverse order or method.

Webster's Revised Unabridged Dictionary

reverse is an informal name for a reverse repurchase agreement.