Main Entry: tri·so·my

Pronunciation: \ˈtrī-ˌsō-mē\

Function: noun

Inflected Form(s): plural tri·so·mies

Etymology: tri- + ³-some + ²-y

Date: 1930

: the condition (as in Down syndrome) of having one or a few chromosomes triploid in an otherwise diploid set

— tri·so·mic \(ˌ)trī-ˈsō-mik\ adjective or noun