allege
Meaning: to assert, usually without proof
Usage: The policeman had alleged that Marshall committed the crime, but after the investigation turned up no evidence, Marshall was set free.
refute
Meaning: to prove wrong
Usage: Maria refuted the president’s argument as she yelled and gesticulated at the TV.
empirical
Meaning: based on observation or experience 2. capable of being proved or disproved by experiment
Usage: That all cats hate getting wet is an empirical statement: I can test it by bathing my cat, Trinket.
incontrovertible
Meaning: indisputable
Usage: Only stubborn Tina would attempt to disprove the incontrovertible laws of physics.