synonym

Short definition from Wiktionary

Noun

1. 1
   A term (word or phrase) which is synonymous with others.
2. 2
   Any of the various names that could in theory be used for a taxon in accordance with the relevant rules: The subset of those names other than the one to be used according to the rules.
3. 3
   Any of the various names that could in theory be used for a taxon in accordance with the relevant rules: Any name that has been applied to a taxon other than the one to be used, including those not allowed by the rules such as misspellings or nomina nuda.
4. 4
   An alternative (often shorter) name defined for an object in a database.

Verb

1. 1
   To make synonymous.