n.
Pronunciation: ˌ in-tr ə - ' gre-sh ə n
Function: noun
Etymology: intro- + -gression (as in regression )
Date: 1938
: the entry or introduction of a gene from one gene complex into another (as by hybridization)
– in · tro · gres · sant \ - ' gre-s ə nt \ adjective or noun
– in · tro · gres · sive \ - ' gre-siv \ adjective