Informant

Part of speech: noun (n.)

1. One who, or that which, informs, animates, or vivifies. [Obs.] Glanvill.

2. One who imparts information or instruction.

3. One who offers an accusation; an informer. See Informer. [Obs. or R.] It was the last evidence of the kind; the informant was hanged. Burke.