Whereas: Definition and part of speech

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.
adv. At which place; where.
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.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.

adv. Which time; then; — used elliptically as a noun.
adv. At what time; — used interrogatively.
adv. At what time; at, during, or after the time that; at or just after, the moment that; — used relatively.
adv. While; whereas; although; — used in the manner of a conjunction to introduce a dependent adverbial sentence or clause, having a causal, conditional, or adversative relation to the principal proposition; as, he chose to turn highwayman when he might have continued an honest man; he removed the tree when it was the best in the grounds.

adv. From what or which place, source, material, cause, etc.; the place, source, etc., from which; — used relatively.
adv. From what place; hence, from what or which source, origin, antecedent, premise, or the like; how; — used interrogatively.