Trig \TRIG\ , adjective;
1. Neat, trim, smart
2. In good physical condition; sound; well
1. To make neat or trim
1. A wedge or block used to prevent a wheel, cask, or the like from rolling
This word dates to the 1200's as "smart, trim" from Old Norse tryggr ("firm, trusty, true"), which ultimately derives from Proto-Indo-European *dru- ("tree"). *Dru- is also the forebear of true.
Today's word and the first definition were both taken from Dictionary.com's 'Word of the Day' for Monday, July 11
Etymologies come from the Oxford English Dictionary and/or Etymonline.com