inform against someone Definition

inform
verb informed, informing

tr & intr
1. To give them knowledge or information about it; to tell them about it.

Thesaurus: tell, relate, instruct, teach, notify.
Form: inform someone about something (especially)
Form: inform someone of something
2. literary or formal
To animate, inspire, or give life to something.
3. formal
To give an essential quality to something.

Etymology: 14c: from Latin informare to give form to or describe.

Phrasal Verb: inform against or on someone

To give incriminating evidence about them to the authorities. See also grass (verb 3), shop (verb 2).