I. ˈdeth-ˌwäch noun
Etymology: death + watch (timepiece); from the superstition that its ticking presages death
Date: 1646
: a small insect that makes a ticking sound ; especially : deathwatch beetle
II. noun
Etymology: death + watch (vigil)
Date: circa 1890
1. : a vigil kept over the dead or dying
2. : the guard set over a criminal to be executed