outbreeding depression
Rare technical term in biology/genetics. Refers to reduced fitness when genetically distant individuals mate, often due to breaking of coadapted gene complexes or local adaptation.
Outbreeding depression refers to the phenomenon where offspring fitness declines due to mating between distantly related individuals.
Inbreeding depression (reduced fitness from mating between close relatives), the opposite of outbreeding depression.
Compound of 外交 (outcrossing) + 弱勢 (depression, weakness). The exact derivation is uncertain; the term appears to be a direct translation of the English biological term 'outbreeding depression'.