In Spanish, the right side of a ship (and everything beyond said side) is called «estribor». I know enough about sailing to guess that it can't possibly have anything to do with a «estribo» (which is where you put your feet when you ride a horse). So more than once I've wondered: maybe «estribor» comes from English «starboard»?
I've done my fair bit of research:
- RAE dictionary says «estribor» comes from old French «estribord». However, I've checked the etymology for modern French «tribord» on some French dictionaries and they say it comes from «stirbord» instead; no references to «estribord».
- NGRAM has nothing for «estribor» before ~1740...
- ... but CORDE has registered uses for «estribor» from as early as 1525. Then again, I highly doubt that «estribor» was already written like that in early 16th century.
- Finally, the Lexicon Tetraglotton, an English-Italian-French-Spanish dictionary from 1660, says Spanish for «starboard» in s. XVII was «estroiborda». Probably a mistake, but there's that.
So... I'm aware that most European words for «right side of ship» come from some old Indo-Germanic-Something root meaning «the side of the steering stick». But where does the current writing of «estribor» come from?