Whether

1. conj. In case; if; — used to introduce the first or two or more alternative clauses, the other or others being connected by or, or by or whether. When the second of two alternatives is the simple negative of the first it is sometimes only indicated by the particle not or no after the correlative, and sometimes it is omitted entirely as being distinctly implied in the whether of the first.
2. pron. Which (of two); which one (of two); — used interrogatively and relatively.

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.