In heating and cooling systems, a vent that returns cold air to be warmed. In a hot-air furnace system, the return is located near an inside wall.
Merriam-Webster Online Dictionary
return (verb)intransitive verb
1.
a) to go back or come back again - return home
b) to go back in thought, practice, or condition - revert
2.
to pass back to an earlier possessor
3.
transitive verb
- reply retort
1.
a) to give (as an official account) to a superior
b) British to elect (a candidate) as attested by official report or - returns
c) to bring back (as a writ or verdict) to an office or tribunal
2.
a) to bring, send, or put back to a former or proper place
b) to restore to a former or to a normal state
3.
a) to send back - visit usually used with on or upon
b) obsolete - retort
4.
to bring in (as profit) - yield
5.
a) to give or perform in return - repay return a compliment , also to respond to in kind - returned his calls
b) to give back to the owner
c) - reflect return an echo
6.
to cause (as a wall) to continue in a different direction (as at a right angle)
7.
to lead (a specified suit or specified card of a suit) in response to a partner's earlier lead
8.
a) to hit back (a ball or shuttlecock)
b) to run with (a football) after a change of possession (as by a punt or a fumble) reciprocate
1.
a) the act of coming back to or from a place or condition
b) a regular or frequent - returning recurrence
2.
a) (1) the delivery of a legal order (as a writ) to the proper officer or court
(2) an endorsed certificate stating an official's action in the execution of such an order
(3) the sending back of a commission with the certificate of the commissioners
b) an account or formal report
c) (1) a report of the results of balloting - usually used in plural election returns
(2) an official declaration of the election of a candidate
(3) chiefly British - election
d) (1) a formal statement on a required legal form showing taxable income, allowable deductions and exemptions, and the computation of the tax due
(2) a list of taxable property
3.
a) the continuation usually at a right angle of the face or of a member of a building or of a molding or group of moldings
b) a means for conveying something (as water) back to its starting point
4.
a) a quantity of goods, consignment, or cargo coming back in exchange for goods sent out as a mercantile venture
b) the value of or profit from such venture
c) (1) the profit from labor, investment, or business - yield
(2) - results
d) the rate of profit in a process of production per unit of cost
5.
a) the act of returning something to a former place, condition, or ownership - restitution the return of stolen goods
b) something - returned , especially unsold publications returned to the publisher for cash or credit
6.
a) something given in repayment or reciprocation - a return on their years of hard work
b) - answer retort
7.
an answering play as
a) a lead in a suit previously led by one's partner in a card game
b) the action or an instance of returning a ball (as in football or tennis)
8.
chiefly British - round-trip
1.
a) having or formed by a change of direction - a return facade
b) doubled on itself - a return flue
2.
a) played, delivered, or given in return - return fire from the enemy
b) taking place for the second time - a return meeting for the two champions
3.
used or taken on - returning the return road
4.
returning or permitting return - a return valve
5.
of, relating to, or causing a return to a place or condition - use the prestamped return envelope
return (Wikipedia)