dis·prove 
(dĭs-prv)
(dĭs-prv)tr.v. dis·proved, dis·prov·ing, dis·proves
To prove to be false, invalid, or in error; refute.
[Middle English disproven, from Old French desprover : des-, dis- + prover, to prove; see PROVE.]
dis·prova·ble adj.
dis·proval n.