deflate

from The American Heritage® Dictionary of the English Language, 5th Edition.

• intransitive verb To release contained air or gas from.
• intransitive verb To collapse by releasing contained air or gas.
• intransitive verb To reduce or lessen the size or importance of.
• intransitive verb To reduce the amount or availability of (currency or credit), effecting a decline in prices.
• intransitive verb To produce deflation in (an economy).
• intransitive verb To be or become deflated.

from The Century Dictionary.

• To remove the air from: the opposite of inflate.

from the GNU version of the Collaborative International Dictionary of English.

• transitive verb To reduce from an inflated condition; used literally and metaphorically.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb transitive To cause an object to decrease or become smaller in some parameter, e.g. to shrink
• verb transitive (economics) To reduce the amount of available currency or credit and thus lower prices.
• verb intransitive To become deflated.
• verb transitive To let down or disappoint.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb release contained air or gas from
• verb reduce or cut back the amount or availability of, creating a decline in value or prices
• verb produce deflation in
• verb become deflated or flaccid, as by losing air
• verb collapse by releasing contained air or gas
• verb reduce or lessen the size or importance of