Guitar
The word guitar was adopted into English from Spanish word guitarra in the 1600s. In the Middle Ages the word gitter or gittern was used in England. Both guitarra and gitter came from the Latin word cithara. The word cithara came from the earlier Greek word kithara. Kithara could have come from the Persian word sehtār.  seh meaning "three" and tār meaning "string".  There is also a similar but two-stringed Persian instrument named dotār. do means "two" in Persian.  The Indian sitar instrument was named after the Persian sehtār. The sihtar itself is related to the Indian instrument, the sitar.