coho UK /ˈkəʊhəʊ/US /ˈkoʊhoʊ/ noun1 •An anadromus and semelparous salmon, Oncorhynchus kisutch, found in the coastal regions of the northern Pacific Ocean, used as a symbol by several Native American tribes.Overall, OCN coho constitute the largest aggregate of coho populations in the United States outside Alaska. — 1996 formscohos