from The American Heritage® Dictionary of the English Language, 4th Edition
- conj. Inasmuch as; in view of the fact: Seeing that you're already at the door, I suppose I must invite you inside.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- v. Present participle of see.
- adj. Having vision; not blind.
- n. The action of the verb to see; eyesight.
- n. The movement or distortion of a telescopic image as a result of turbulence in the Earth's atmosphere.
- conj. Inasmuch as; in view of the fact that.
from the GNU version of the Collaborative International Dictionary of English
- In view of the fact (that); considering; taking into account (that); insmuch as; since; because; -- followed by a dependent clause.
from The Century Dictionary and Cyclopedia
- Because; inasmuch as; since; considering; taking into account, or in view of the fact (with that expressed or understood).
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. normal use of the faculty of vision
- adj. having vision, not blind
- n. perception by means of the eyes
see + -ing (Wiktionary)
Probably an elision of "seeing that" or "seeing as". (Wiktionary)