a person who stumbles, stammers, or stutters over their words in conversation. a person who is nervous.
This happens when a person is speaking and either repeats a syllable or two, or even a grunt-like noise, in place of an actual word, and of course you know what they are trying to say, but you need to wait. A general nervous or anxious person. Thus, they are a flumberbuck!
di Nikki 6 15 marzo 2009