The Spanish word 'tilapia' comes from the Tswana word 'tlhapi', which simply means 'fish'. Tswana is a Bantu language spoken in southern Africa, particularly in Botswana and South Africa. When this African word was borrowed into Spanish and other languages, it became specifically associated with this genus of freshwater fish that is native to Africa.

There are no simpler or more common Spanish words that are etymologically related to 'tilapia', as it is a direct borrowing from an African language.

The English word 'tilapia' is also borrowed from the same Tswana source. Both Spanish and English adopted this word to refer to this specific type of fish, which has become popular in cuisine worldwide.