Deathwatch \Death"watch`\ (?; 224), n.

1. (Zo["o]l.)
   (a) A small beetle (Anobium tessellatum and other allied species). By forcibly striking its head against woodwork it makes a ticking sound, which is a call of the sexes to each other, but has been imagined by superstitious people to presage death.
   (b) A small wingless insect, of the family Psocid[ae], which makes a similar but fainter sound; -- called also deathtick.

She is always seeing apparitions and hearing deathwatches. --Addison.

I did not hear the dog howl, mother, or the deathwatch beat. --Tennyson.

2. The guard set over a criminal before his execution.

Source: Webster's Revised Unabridged Dictionary (1913)