-ˌfī verb
( -ed/-ing/-es )
Etymology: Middle English testifien, from Latin testificari, from testis witness + -ficare -fy — more at testament
intransitive verb
1.
a. : to make a statement based on personal knowledge or belief : bear witness
I can testify as to the vital influences that reading had upon our thinking — C.R.Woodward
of such enormous importance was the birth of a child in the imperial family that there must be many witnesses … to testify to having seen the birth — P.I.Wellman
the Quakers had long been testifying against the abuses — H.S.Canby
b. : to serve as evidence : constitute a proof
renaissance of the trade fair testifies to the rapid recovery of European economies — Modern Industry
shattered gateways … testify to the existence of a population at this remote spot — Norman Douglas
two major works … testify to his industry as well as to his high standards of scholarship — L.P.Kirwan
2. : to express a personal conviction
suffered the worst and emerged to testify without rancor to the dignity of the spirit — Gordon Harrison
especially : to affirm one's regeneration by the grace of God
hear reformed sinners testify — Green Peyton
3. : to make a solemn declaration under oath for the purpose of establishing a fact (as in a court) : give testimony according to the law of legal procedure
a neighbor testified against the accused man — B.L.K.Henderson
called to testify before a congressional fact-finding committee
transitive verb
1.
a. : to support the truth of (a statement) : bear witness to (a fact) : attest
everyone who has ever worked in the editorial sanctum will testify that her story … has the true ring of experience — Atlantic
the college demands a letter testifying that the student is of good moral character — W.A.Lunden
b. : to serve as evidence of : prove
thy breath shall testify thou livest — Shakespeare
that it is of no recent date is testified by the age of the tree whose roots surrounded it — American Guide Series: Minnesota
2. archaic
a. : to make known (a personal conviction) : affirm , profess
testify their faith therein openly and aloud — P.E.F.W.Smythe
b. : to give evidence of : show
could not better testify my respect for your sister — Charles Dickens
3. : to declare under oath before a tribunal or officially constituted public body
Synonyms: see swear