n.
1 a channel through which metal or plastic is poured into a mould.
2 a piece of metal or plastic which has filled a sprue and solidified there.
Etymology: 19th c.: orig. unkn.
2.
n. a tropical disease with ulceration of the mucous membrane of the mouth and chronic enteritis.
Etymology: Du. spruw THRUSH(2); cf. Flem. spruwen sprinkle
Useful english dictionary. 2012.