Designated or distinguished by, or as by, a mark; hence; noticeable; conspicuous; as, a marked card; a marked coin; a marked instance.
Distinguished from the basic form (e.g., the singular) by the presence of a particular linguistic feature (e.g., /s/ indicating the plural) or, as in phonology, for example, of the two phonemes /t/ and /d/, the /d/ is marked because it exhibits the feature of voice.