Wittol

1. n. A man who knows his wife’s infidelity and submits to it; a tame cuckold; — so called because the cuckoo lays its eggs in the wittol’s nest.
2. n. The wheatear.

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.