The Spanish word 'sha' comes directly from the Persian word 'shah', meaning 'king' or 'sovereign'. This term specifically refers to the former monarchs of Iran (Persia), who ruled under the title of Shah until the Iranian Revolution in 1979. The Spanish language adopted this word while maintaining its original meaning, though simplifying the spelling to match Spanish phonetic patterns by dropping the final 'h'.

There are no common Spanish words that are etymologically related to 'sha', as it is a direct borrowing from Persian that refers specifically to Persian rulers.

The English word 'shah' is directly related, being borrowed from the same Persian source. English retained the original Persian spelling with the final 'h'. You might also recognize this word in 'checkmate', which comes from Persian 'shah mat' meaning 'the king is helpless' - literally 'the shah is dead'.