to be or give clear proof of something

affirm, vouch for

to prove beyond doubt the origin etc of (something)

establish as real, genuine

to state, show, the truth of (opinions, feelings etc)

ratify, validate, prove

to give support go certainty to (a statement, belief, theory etc)

back up information, story

to show that (a person, statement, act etc) is right, reasonable or proper

legitimize, substantiate

to supply proof of (something); show (something) beyond doubt to be true

establish facts; put to a test

tested and known to be true, successful

establish facts; put to a test

to give one's formal approval to (an agreement) by signing etc

affirm, authorize

to provide facts to support (a claim, statement, charge etc)

back up a statement, idea

to make (something) valid

ascertain the truth, authenticity of something

to test the truth or accuracy of (a report etc); (of an event etc) to prove, show, the truth of (something)

confirm, validate

to show or provide the truth, justice, validity etc of (something that has been attacked or disputed)

prove one's innocence