from The American Heritage® Dictionary of the English Language, 4th Edition
- transitive v. To support from below, as with props, girders, or masonry.
- transitive v. To give support or substance to: "the public awareness that must underpin a sustained and concerted development effort for Africa and its youth” ( Barber B. Conable).
from Wiktionary, Creative Commons Attribution/Share-Alike License
- v. To support from below with props or masonry.
- v. To give support to; to corroborate.
from the GNU version of the Collaborative International Dictionary of English
- transitive v. To lay stones, masonry, etc., under, as the sills of a building, on which it is to rest.
- transitive v. To support by some solid foundation; to place something underneath for support.
from The Century Dictionary and Cyclopedia
- To pin or support underneath; place something under for support or foundation when a previous support is removed; underset; hence, figuratively, to support; prop.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- v. support with evidence or authority or make more certain or confirm
- v. support from beneath
under- + pin (Wiktionary)