A steward is an official who is appointed by the legal ruling monarch to represent him or her in a country, and may have a mandate to govern it in his or her name; in the latter case, it roughly corresponds with the position of governor or deputy (the Roman rector, praefectus or vicarius).
From Old English stíweard, stiȝweard, from stiȝ "hall, household" + weard "wikt:warden, keeper"; corresponding to Dutch: stadhouder, German Statthalter "place holder", a Germanic parallel to French lieutenant.
The Old English term stíweard is attested from the 11th century. Its first element is most probably stiȝ- "house, hall" (attested only in composition; its cognate stiȝu is the ancestor of Modern English sty). Old French estuard and Old Norse stívarðr are adopted from the Old English.
The German and Dutch term (Middle High German stat-halter) is a parallel but independent formation (a calque of lieutenant) corresponding to obsolete English stead holder (stede haldare 1456; also stedys beryng (1460), sted-haldande (1375) steadward, steadsman).
In medieval times, the steward was initially a servant who supervised both the lord's estate and his household.
http://en.wikipedia.org/wiki/Tributary
A tributary or affluent is a stream or river that flows into a main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean.
http://en.wikipedia.org/wiki/Jelly_roll_%28battery%29
