It could be used, yes and would be understandable. Here are some more synonys: assumptive, arrogant, cavalier, chesty, haughty, highfalutin (also hifalutin), high-and-mighty, high-handed, high-hat, huffish, huffy, imperious, important, lofty, lordly, masterful, overweening, peremptory, pompous, presuming, presumptuous, pretentious, self-asserting, self-assertive, sniffy, stiff-necked, supercilious, superior, toplofty (alsotoploftical), uppish, uppity.
My boyfriend's bumptious and assertive personality is one of the reasons why we sometimes have trouble agreeing.The bumptious six year old grabbed the toy from his little brother.
The policeman had a bumptious attitude that was very repulsive to vulnerable women.
arrogantly, contemptuously, haughtily, insolently http://thesaurus.reference.com/browse/proudly
Being an artificial coinage, Rambunctious does not really have a root word. The word was made up from another made-up word rumbustious, which is a whimsical variant of the earlier robustious (oaken-strong, valiant), possibly under the influence of rum, or of rumble.
Superb is another word for excellent. Superb is another word for excellent.
He is a very bumptious young man.
Bumptious
My boyfriend's bumptious and assertive personality is one of the reasons why we sometimes have trouble agreeing.The bumptious six year old grabbed the toy from his little brother.
egotistic, conceited, bumptious, imperious, hubristic
The policeman had a bumptious attitude that was very repulsive to vulnerable women.
Scrumptious.
Bumptious as a Fireman - 1910 was released on: USA: 16 September 1910
Bumptious as Romeo - 1911 was released on: USA: 1 February 1911
His behaviour was so annoying and insulting that he could only be described as being a bumptious person.
The Joke They Played on Bumptious - 1910 was released on: USA: 21 December 1910
Mr- Bumptious on Birds - 1910 was released on: USA: 7 June 1910
Bumptious Takes Up Automobiling - 1910 was released on: USA: 19 August 1910