Sley (?), n. [AS. sl&unr_;, fr. sleán to strike. See Slay, v. t.] 1. A weaver's reed. [Spelt also slaie.]
[1913 Webster]

2. A guideway in a knitting machine. Knight.
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3. (Weaving) The number of ends per inch in the cloth, provided each dent in the reed in which it was made contained an equal number of ends. E. Whitworth.
[Webster 1913 Suppl.]