n.
Pronunciation: ' ek- ˌ sän
Function: noun
Etymology: ex pressed sequence + 2 -on
Date: circa 1978
: a polynucleotide sequence in a nucleic acid that codes information for protein synthesis and that is copied and spliced together with other such sequences to form messenger RNA ― compare INTRON
– ex · on · ic \ ek- ' sä-nik \ adjective