ETYMOLOGY
from clatter (to talk rapidly and noisily; to talk idly; to chatter, prattle, babble) + fart (a disagreeable or annoying person)
EXAMPLE
“…The Irish enimie spieng that the citizens were accustomed to fetch such od vagaries, especiallie on the holie daies, & hauing an inkling withall by some false clatterfert or other, that a companie of them would haue ranged abrode, on mondaie in the Easter weeke towards the wood of Cullen…”
From: The firste (laste) volume of the Chronicles of England, Scotlande, and Irelande
– Raphael Holinshed, Richard Stanyhurst, 1577
Lexicophilia 