[v] establish the validity of something, as by an example, explanation or experiment; "The experiment demonstrated the instability of the compound"; "The mathematician showed the validity of the conjecture"
[v] provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes; "His high fever attested to his illness"; "The buildings in Rome manifest a high level of architectural sophistication"; "This decision demonstrates his sense of fairness"
[v] show or demonstrate something to an interested audience; "She shows her dogs frequently"; "We will demo the new software in Washington"
[v] march in protest; take part in a demonstration; "Thousands demonstrated against globalization during the meeting of the most powerful economic nations in Seattle"
attest, certify, demo, establish, evidence, exhibit, manifest, march, present, prove, shew, show, show