Two things share this spelling, and the sense you want here is the cloth one. Candlewick is a thick cotton fabric decorated with rows of raised loops or tufts of thread standing up from the surface, so it feels bumpy and soft under your hand. It was made from the same fat, loosely twisted cotton yarn used for candle wicks, which is where the name came from. You meet it most as a candlewick bedspread — the heavy white or pastel cover on a bed, very common in British and American homes from about the 1930s to the 1970s. Because of that, the word carries a smell of grandmothers' houses for many speakers; it sounds a bit old-fashioned, and younger people may not know it. Use it before a noun most of the time: candlewick bedspread, candlewick cushion. As a material name it is uncountable — you say 'made of candlewick', not 'a candlewick'. The other, older and more literal meaning is simply the wick of a candle: the string in the middle that you light. Both meanings are alive, so context decides. If someone says 'wash the candlewick', they mean the bedspread; if they say 'trim the candlewick', they mean the string.

（此義）簇絨棉布、燭芯紗織品 — 最常見的是 candlewick bedspread「毛球（簇絨）床罩」，早年常見的白色凸紋床單。另一義為蠟燭的燭芯。