Whereas(adv.) At which place; where.
Whereas(conj.) Considering that; it being the case that; since; -- used to introduce a preamble which is the basis of declarations, affirmations, commands, requests, or like, that follow.
Whereas(conj.) When in fact; while on the contrary; the case being in truth that; although; -- implying opposition to something that precedes; or implying recognition of facts, sometimes followed by a different statement, and sometimes by inferences or something consequent.

Words within whereas