'Pegar' is a Spanish slang term that, depending on context, can mean 'to hit' or 'to stick', but in a colloquial context, it often means 'to have an effect', 'to catch on' or 'to fall asleep'.
Examples
- Spanish: Esta canción va a pegar en todas las discotecas este verano.
- English: This song is going to catch on in all the clubs this summer.