The snuff or burnt wick of a candle.
1552. Huloet, Snuffer of a candle or candlesnuffe.
1683. Chalkhill, Thealma & Cl., 102. Her eyes like Candle-snuffs by age sink quite Into their Sockets.
1880. Syd. Soc. Lex., Candle snuff
has been recommended for the cure of ague.