Candlefish \Can"dle*fish`\, n. (Zo["o]l.) (a) A marine fish ({Thaleichthys Pacificus}), allied to the smelt, found on the north Pacific coast; -- called also {eulachon}. It is so oily that, when dried, it may be used as a candle, by drawing a wick through it. (b) The beshow.