The Spanish word 'pasa' (meaning 'raisin') comes from the Latin word 'passa', which was the feminine form of the past participle meaning 'spread' or 'dried'. This derives from the Latin verb 'pandere' meaning 'to spread or extend'. The connection between spreading and raisins makes sense when you consider that grapes were traditionally spread out in the sun to dry them into raisins.

A related Spanish word is 'paso' meaning 'step' or 'passage', which shares the same Latin root of something being spread or extended. You can also find this root in 'pasillo' (hallway) and 'pasear' (to walk, to stroll).

In English, we can find this same Latin root in words like 'expand' (from ex- + pandere), 'expanse', and 'pace' (which came through Old French from the same Latin family). The common thread among these words relates to spreading out or extending in space.