(In nomenclature) a surplus scientific name, belonging to a taxon which already has a valid name; where two or more names are applied to the same taxon they are called synonyms but only one of these can be correct — usually this is the oldest (principle of priority) but the correct name may be a conserved or non-rejected name; there are two kinds of synonyms.
A scientific name which, though no longer valid, still lingers in use, for example Plumbago aunculata syn. P. capensis.
Another name a plant was given, incorrectly applied and not valid.
A scientific name which, though no longer accepted, still lingers in use, Cyrtostachys renda syn. C. lakka.
One of two words that have the same or very similar meaning; an additional or substitute name for the same disease, sign, symptom, or anatomical structure.