Definition - inclined to dispute
Disputatious may refer to your friend’s tendency to disagree with every plan you make, but can also take the meaning “marked by disputation (verbal controversy)” or “provoking debate.” Disputatious (and dispute) comes from the Latin disputare, which simply means “to discuss.”
Must have been something rank to have caused Clancy and Johnny to get into a dispute with his umps. They’re not of the disputatious sort.
— Winston-Salem Journal (Winston-Salem, NC), 20 Jun. 1911