allegation Play nounA claim or assertion that someone has done something illegal or wrong, typically one made without proof. SYNONYMS accusationaffirmationargumentassertionattestationavermentavowalcertificationchargeclaimcontentiondeclarationevidencehintimplicationimputationindicationinsinuationintimationpleapretenceproclamationprofessionstatementsuggestiontestimonywitness