To turn left, especially when commanding a horse or other draft animal.
Of uncertain origin, possibly from an old English word imitative of the sound used to direct animals. The opposite of 'gee' (turn right), it's been used for centuries in farming and transport.
Haw is one of the oldest animal commands still in use—farmers have been shouting 'haw!' at horses for over 500 years, and it's pure tradition that the word stuck around!
Complete word intelligence in one call. Free tier — 50 lookups/day.