A fire maintained during the night as a signal, or for the use of a watching party, guard, sentinels, etc.(noun)
The Century Dictionary (Public Domain)
Use "watch-fire" in a sentence
"The watch-fire will be put out at 9: 00 p.m. Saturday, during"
"There was no one about, but round the corner was a watch-fire, with a few pandies and bazaar-wallahs round it; I ambled past them, exchanging a greeting, and they didn't do more than give me an idle glance."
"For three weeks, beginning early in February, the twenty-six women, all “convicts” now from the watch-fire incident, planned to travel to at least fifteen cities."