LYE is a 3 letter word that starts with L.

1. \Lye\, n. [Written also {lie} and {ley}.] [AS. le['a]h; akin
   to D. loog, OHG. louga, G. lauge; cf. Icel. laug a bath, a
   hot spring.]
   A strong caustic alkaline solution of potassium salts,
   obtained by leaching wood ashes. It is much used in making
   soap, etc.
   
   

2. \Lye\, n. (Railroad)
   A short side line, connected with the main line; a turn-out;
   a siding. [Eng.]
   
   

3. \Lye\, n.
   A falsehood. [Obs.] See {Lie}.