From English - German Ding/FreeDict dictionary ver. 1.9-fd1:
witter /wˈɪtə/ <v>
[Br.] [slang] schwafeln, sülzen, schwätzen, labern, quatschen, quasseln <v, intr>
"witter on about sth." - über etw. quatschen
Synonyms: blather, blether, blabber, babble
see: blathering, blethering, blabbering, babbling, wittering, blathered, blethered, blabbered, babbled, wittered