(military) signal to turn the lights out
"The bugler sounded taps, signaling it was time to extinguish all the camplights."
plural of tap
"The plumber installed new water taps to replace the old, leaking ones in the kitchen sink."
Third-person singular simple present indicative form of tap
"She taps her fingers on the table while waiting for her turn to speak."
In plain English: To tap means to hit something lightly with your finger, knuckles, or another object.
"She turns on the taps to get some water for her garden."
A bugle call played by the United States Armed Forces at dusk, during flag ceremonies, and at military funerals.
"The soldier stood at attention as he heard the taps bugle call marking the end of the day."
From tap (noun) + -s. Noun 1 sense 1 ("signal for extinguishing all lights in soldiers' quarters and retiring to bed") is from the fact that the signal was originally made using a drum.