The Spanish word 'rap' comes from English 'rap', which originally meant 'to strike' or 'hit'. The English word can be traced back to the Swedish word 'rappa', meaning 'to hit'. In English, the meaning evolved from physical striking to a style of rhythmic speaking or music, likely due to the percussive nature of the vocal delivery. The Spanish language then borrowed this musical meaning directly from English, specifically referring to rap music and hip-hop culture.

As 'rap' is a relatively recent borrowing from English into Spanish, there aren't any simpler or older Spanish words that share its etymology.

The English word 'rap' is obviously related, both as the direct source of the Spanish word and sharing the same ultimate etymology. In English, 'rap' has maintained both its original meaning of 'to strike' or 'hit' (as in 'rap on the door') and its more recent meaning referring to rhythmic speaking or hip-hop music. The connection between these meanings becomes clear when you consider how rap music involves 'striking' words together in a rhythmic pattern.