Many words are used indiscriminately as nouns, adjectives or verbs, without any change of form.
He's capable of great violence, but he doesn't act indiscriminately.
There can be little doubt that the earlier of these expeditions were from Denmark, though the term Northmen was originally applied indiscriminately to all these terrible visitants from the unknown north.
On both sides was civil war, urged as fiercely as that against the common enemy, in which the parties sought allies indiscriminately among Christians and Mahommedans.
Dogs are bred constantly and indiscriminately.