It is known that when an acid is strong then it dissociates completely into the solution of water. Whereas a strong base also dissociates completely into a solution of water.
Also there is little or no reverse reaction of this dissociation.
On the other hand, if an acid or base is not strong enough or weak acid then it will dissociate slightly or partially in a solution of water.
Therefore, when only 42% of a substance dissociates to release hydronium ions then it means it is a weak acid.
