Borrowed from Livonian kiš (“ruffe”); compare cognates in other Baltic-Finnic languages (Finnish kiiski, Estonian kiisk, kiis (“ruffe”)). This word is already attested in 15th-16th century family names, in 17th-century dictionaries as ķīsa, ķīsis, and from the 18th century on only in its modern form ķīsis.
ķīsis m (2nd declension)
- ruffe (small freshwater fish, especially Gymnocephalus cernuus)
ķīsis barojas ar odu kāpuriem un zivju ikriem ― the ruffe feeds on mosquito larvae and fish eggs