"For every pro there's an equal and opposite con," goes an old joke I just made up. Only it's not true, surprisingly. I found only one pro/con pair in the Macquarie Dictionary (4th, 2005) that were common opposites, protract and contract. But not protractor and contractor in their usual meanings. (For vs. against tractors?) Protest and contest can be opposites, to stretch a point, eg at a politically or morally controversial game. But more commonly they are synonyms: to argue with the umpire. Lastly, might we count the old gag opposites, progress and Congress?
"Pros And Cons,"
Word Ways: Vol. 40
, Article 31.
Available at: https://digitalcommons.butler.edu/wordways/vol40/iss2/31