substantiative

WordReference Random House Learner's Dictionary of American English © 2025

sub•stan•ti•ate /səbˈstænʃiˌeɪt/   v. [~ + object] , -at•ed, -at•ing. 

1. to show or establish (a claim, opinion, etc.) by proof or strong evidence:
   to substantiate a charge.

sub•stan•ti•a•tion /səbˌstænʃiˈeɪʃən/  n. [uncountable] See -stan-.

WordReference Random House Unabridged Dictionary of American English © 2025

sub•stan•ti•ate  (səb stan′shē āt′), v.t., -at•ed, -at•ing. 

1. to establish by proof or competent evidence:
   to substantiate a charge.
2. to give substantial existence to:
   to substantiate an idea through action.
3. to affirm as having substance;
   give body to;
   strengthen:
   to substantiate a friendship.

• Neo-Latin substantiātus (past participle of substantiāre), equivalent. to Latin substanti(a) substance + -ātus -ate¹
• 1650–60

sub•stan′ti•a′ta•ble, adj. 
sub•stan′ti•a′tion, n. 
sub•stan′ti•a′tive, adj. 
sub•stan′ti•a′tor, n. 
Synonyms

• 1. prove, confirm, verify, validate.