One who informs someone else about something. / A person who tells authorities about improper or illegal activity. / One who informs, animates, or inspires.

plural of informer

That which resolves uncertainty; anything that answers the question of "what a given entity is". / Things that are or can be known about a given topic; communicable knowledge of something.

Not formal or ceremonious. / Not in accord with the usual regulations. / Suited for everyday use. / (of language) Reflecting everyday, non-ceremonious usage.

(archaic, transitive) To instruct, train (usually in matters of knowledge). / (transitive) To communicate knowledge to. / (intransitive) To impart information or knowledge.

Without regular form; shapeless; ugly; deformed.

simple past tense and past participle of inform

Instructed; having knowledge of a fact or area of education. / Based on knowledge; founded on due understanding of a situation.

(obsolete) Created, given form. / (obsolete) Unformed or ill-formed; deformed; shapeless. / (astronomy, obsolete) Not included within the figures of any of the ancient constellations.

One who relays confidential information to someone, especially to the police; an informer.