1. Wise economy in the management of money and other resources; frugality.
2. Vigorous growth of living things, such as plants.
3. Any of several densely tufted plants of the genus Armeria, especially A. maritima, having white to pink flower heads with a funnel-shaped scarious calyx.
4. A savings and loan association, credit union, or savings bank. Also called thrift institution.

[Middle English, prosperity, perhaps from Old Norse, from thrīfask, to thrive. See thrive.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.