Rough
Antidiarrheals are the exact opposite of laxatives.
Scaperune is an island that is the exact opposite of Runescape.
The opposite (imprecisely) would be approximately, or roughly.
Irony
I do not belive that the word avenged has an exact opposite, however, the word legitimize would be fairly close. The opposite of getting revenge for a crime, would be to accept that crime as a legal act.
Answer is the exact opposite.
The exact opposite of logical is illogical.
The opposite of hymn is Christian Metal. The exact exact opposite is secular metal (aka songs that have a bunch of swear words, etc.)
Antidiarrheals are the exact opposite of laxatives.
Strength. Forte. (There is no exact opposite.)
A reaction that is the exact opposite of what was therapeutically intended is a paradoxical reaction.
disobedience
No, they are the exact opposite of perverted!
There isn't an exact opposite, but a drain might be a good approximate opposite if you are using it for a poem or a project.
Broad. The exact opposite would be wide.
The exact opposite happens
the exact opposite