gem·i·na·tion \ˌjeməˈnāshən\noun (-s) Etymology: Latin gemination-, geminatio, from geminatus (past participle of geminare) + -ion-, -io -ion : a doubling, duplication, or repetition: as a.: a formation of two teeth from a single tooth germ b. (1): a writing of a letter twice in succession in the spelling of a word (2): a making, becoming, or being geminated