To express disapproval of or regret for; deplore: "Tom Brokaw of NBC News recently bemoaned 'the cancer of the sound bite' afflicting Presidential campaigning"(John Tierney).
[Middle English bimonen, alteration (influenced by mone, moan) of bimenen, from Old English bemǣnan : be-, be- + mǣnan, to complain of; see mei-no- in Indo-European roots.]