My cousin has always been babblative.    From LearnThat.org. 

'Nothing,' he declares, 'in abstract science can be more certain than these propositions,' though they are denied by 'our professors of the arts babblative and scribblative '-- that is, by Benthamites and Whigs.    From Wordnik.com.  [The English Utilitarians, Volume II (of 3) James Mill] Reference