Haw

Haw \HAW\ , verb;
1. To utter a sound representing a hesitation or pause in speech
2. To turn or make a turn to the left
noun;
1. A sound or pause of hesitation
2. The fruit of the Old World hawthorn, Crataegus laevigata, or of other species of the same genus
interjection;
1. Used as a word of command to a horse or other draft animal, usually directing it to turn to the left

There are a lot of definitions and uses for haw and a number of etymologies for the different uses. The verb haw, meaning "hesitate in speech" is first attested in the 1580's and is imitative in origin. The noun of the same sense evolved by the 1600's. Haw as in "the fruit of the hawthorn" is of uncertain origins, but may be short for hægberie ("hedge-berry"). If so, it dates to around the year 1000. Using haw to direct horses is first attested in 1843, though it is probably much older, and the Oxford English Dictionary offers no etymology for it at all.

Some other definitions:
1. A hedge or encompassing fence (Old English haga < Proto-Germanic *hagon)
2. The 'third eyelid' of a dog, horse, etc. (first attested in 1523, of uncertain origin)
3. Bluish, grayish; discolored (Old English hæwi, related to hæwen meaning "blue")

Today's word and the first definition were both taken from Dictionary.com's 'Word of the Day' for Thursday, June 30
Etymologies come from the Oxford English Dictionary and/or Etymonline.com