from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Equivalent in effect or value: a request tantamount to a demand.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- v. To amount to as much; to be equivalent.
- n. Something which has the same value or amount (as something else). (attributive use passing into adjective, below)
- adj. Equivalent in meaning or effect.
from the GNU version of the Collaborative International Dictionary of English
- adj. Equivalent in value, signification, or effect.
- intransitive v. To be tantamount or equivalent; to amount.
from The Century Dictionary and Cyclopedia
- To be tantamount or equivalent.
- Equivalent, as in value, force, effect, or signification.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. being essentially equal to something
From obsolete tantamount, an equivalent, from Anglo-Norman tant amunter, to amount to as much : tant, so much, so great (from Latin tantum, neuter of tantus, from tam, so; see to- in Indo-European roots) + amunter, to amount to, variant of Old French amonter; see amount.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Anglo-Norman tant amunter. (Wiktionary)