De gustibus non disputandum est is a Latin maxim. It means “one must not dispute about tastes.” (literally, "tastes are not disputable", or even more so, "There will not be a disputing of tastes.") [1][2] The implication is that opinions about matters of taste are not objectively right or wrong, and hence that disagreements about matters of taste cannot be objectively resolved.
This phrase is famously misquoted in Act I of Anton Chekhov's play The Seagull. The character Shamrayev conflates it with the phrase de mortuis nil nisi bonum (in the alternate form: de mortuis, aut bene aut nihil – "of the dead, either [speak] good or [say] nothing"), resulting in "de gustibus aut bene, aut nihil", "Let nothing be said of taste but what is good".[3]
It is also notably, deliberately mis-translated in Laurence Sterne's "The life and opinions of Tristram Shandy, gentleman": in which the narrator states; "DE GUSTIBUS NON EST DISPUTANDUM;—that is, there is no disputing against Hobby-Horses; and for my part, I seldom do".