overdominant

From over- +‎ dominant.

overdominant (comparative more overdominant, superlative most overdominant)

1. Excessively dominant.
   • 1991, Richard Evan Jones, Human Reproductive Biology, page 451:

     What would cause this reversal in a male's development? One possible answer could be that an overdominant mother is seductive to the child, and the father is weak and detached.

2. (genetics) Exhibiting overdominance.

• “overdominant”, in Collins English Dictionary.