English▸ verb [no object] talk foolishly or incessantly:
he was yammering on as if he had an enthralled audience at his feet
it seems not only boring but also pointless to keep yammering away about it.
▪ make a loud, repetitive noise:
the seismographs were yammering for days.
▸ noun [mass noun] foolish or incessant talk:
the look on his face stopped Bob's nervous yammer
the yammer of their animated conversation.
▪ loud and sustained or repetitive noise:
the yammer of enemy fire.
– ORIGIN late Middle English (as a verb meaning ‘lament, cry out’): alteration of earlier yomer, from Old English geōmrian ‘to lament’, suggested by Middle Dutch jammeren.