sub·dom·i·nant 
(sŭb-dŏmə-nənt)
(sŭb-dŏmə-nənt)n.
Music
Music
The fourth tone of a diatonic scale, next below the dominant.
adj.
1. Zoology Less than dominant; ranking below one that is dominant: the subdominant male in a pride of lions.
2. Ecology Prevalent in a community but below the dominant in importance. Used of a species.