Entry 1 sense Webster, 1913 Disloyalty /dĭs-loi'-əl-tē/ · Dis·loy·al·ty · IPA /dɪsˈlɔɪ.(j)əɫ.ti/ 01 n. Want of loyalty; lack of fidelity; violation of allegiance. 1. Want of loyalty; lack of fidelity; violation of allegiance.