bea·con 
(bēkən)
(bēkən)n.
1.
a. A signal fire, especially one used to warn of an enemy's approach.
b. A signaling or guiding device that emits light, such as a lighthouse.
c. A radio transmitter that emits a characteristic guidance signal for aircraft.
d. A signaling device that emits a repeating sound; a pinger.
2. A source of guidance or inspiration: a beacon of hope.
tr. & intr.v. bea·coned, bea·con·ing, bea·cons
To provide with or signal as a beacon.
[Middle English beken, from Old English bēacen; see bhā-1 in the Appendix of Indo-European roots.]