[Etymology unknown; perh. senses 1 and 2 do not belong to the same word.]
1. A ‘knot’ in cloth.
1464. Act. 4 Edw. IV., c. 1. En cas que ascune autiel diversite ou Rawe, Skawe, cokell ou fagge, aveigne destre en ascun part des ditz draps.
1858. Simmonds, Dict. Trade, Fag, one who works hard; a knot in cloth.
2. A parasitic insect which infects sheep; a sheep-tick; hence a disease of sheep. Also, sheep-fag. dial. attrib. fag-water (see quot.).
1789. Projects in Ann. Reg., 71 Hippobosca ovina, called in Lincolnshire sheep faggs.
1877. N. W. Linc. Gloss., Sheep-fag, a parasitic insect that infests the wool of sheep.
1886. S. W. Linc. Gloss., Fag-water, water mixed with arsenic and soft-soap in which sheep are dipped to kill the ticks.
