The Spanish word 'diosa' meaning 'goddess' comes from the Spanish masculine word 'dios' (meaning 'god') combined with the feminine suffix '-a'. The word 'dios' itself derives from the Latin word 'deus', meaning 'god'. This is a straightforward example of how Spanish forms feminine nouns by adding the suffix '-a' to masculine nouns ending in '-os'.

The most obvious related Spanish word is 'dios' (god), which is the masculine form. You might also encounter words like 'divino/divina' (divine) and 'divinidad' (divinity) which share the same religious root, though these come through slightly different Latin pathways.

While English 'deity' and 'divine' are related to Spanish 'diosa', they come from the same Latin root 'deus' through different paths. The English word 'deity' comes from Latin 'deitas', and 'divine' from Latin 'divinus', both ultimately related to 'deus'. You can see how the concept of godhood is preserved in all these related words across both languages.