That can be argued; that can be proven or strongly supported with sound logical deduction, precedent, and evidence.
2
Open to doubt, argument or debate.
This led to a set of rules (play cannot begin before crossing East Blithedale Avenue), then subrules ("crossing" means reaching the always arguable halfway point of the avenue) […
This led to a set of rules (play cannot begin before crossing East Blithedale Avenue), then subrules ("crossing" means reaching the always arguable halfway point of the avenue) […
Wiktionary
02
Your conclusion is highly arguable.
Tatoeba · #17248
03
Everything is arguable.
Tatoeba · #645580
Usage Notes
i Register
In some senses, arguable is marked as colloquial. Watch for register when choosing this word.