Whence

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

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.