Tantamount a. : Equivalent in value, signification, or effect.

Tantamount v. i. : To be tantamount or equivalent; to amount.

Example:
What was James Rachels trying to say about Tantamount?

Taxonomy
Dictionary, Synonyms, adjective, word origin, obs, tantus, tam, amonter, Houghton Mifflin Company, free online English dictionary, dictionary results, pronunciation, Random House Dictionary, free online dictionary, definitions, websters, spelling, vocabulary.

Defination from the web:
Tantamount - Definition of Tantamount at Dictionary.com a free online dictionary with pronunciation, synonyms, and translation of Tantamount. ... [From obsolete tantamount, an equivalent, from Anglo-Norman tant amunter, to amount to as much : tant, so much, so great (from Latin tantum, ...