from what place, source, or cause?; from where?: whence does he find his strength?
conjunction
from what place, source, or cause: I know whence he comes
from which place, source, or cause: we went home, whence we departed soon after
to the place from which: return whence you came
from which fact: there was no reply, whence he inferred that all had gone
pronoun
a place, cause, etc.: preceded by from: its use is still frowned on by some
See whence in American Heritage Dictionary 4
(hwĕns, wĕns)
adverb
From where; from what place: Whence came this traveler?
From what origin or source: Whence comes this splendid feast?
conjunction
Out of which place; from or out of which.
By reason of which; from which: The dog was coal black from nose to tail, whence the name Shadow.
Usage Note: The construction from whence has been criticized as redundant since the 18th century. It is true that whence incorporates the sense of from: a remote village, whence little news reached the wider world. But from whence has been used steadily by reputable writers since the 14th century, most notably in the King James Bible: “I will lift up mine eyes unto the hills, from whence cometh my help” (Psalms). Such a respectable precedent makes it difficult to label the construction as incorrect. Still, it may be observed that whence (like thence) is most often used nowadays to impart an archaic or highly formal tone to a passage, and that this effect is probably better realized if the archaic syntax of the word—without from—is preserved as well.