Praxis

Praxis \PRAK-sis\ , noun;
1. Practice, as distinguished from theory; application or use, as of knowledge or skills
2. Convention, habit, or custom
3. A set of examples for practice

This word dates to the 1580's from Middle Latin praxis ("practice, action"), which derives from Greek praxis ("practice, action, doing") from the stem of prassein ("to do, act").

Today's word and the first definition were both taken from Dictionary.com's 'Word of the Day' for Wednesday, April 13
Etymologies come from the Oxford English Dictionary and/or Etymonline.com