Lye

• POS: Noun

CIDE DICTIONARY

Lye, n. [AS. leáh; 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.  [1913 Webster]
•  Sodium hydroxide or potassium hydroxide, or a concentrated aqueous solution of either compound.  [PJC]

Lye, n. 

 A short side line, connected with the main line; a turn-out; a siding.  [1913 Webster]

Lye, n. 

 A falsehood.  [1913 Webster]

OXFORD DICTIONARY

Lye, n.
1 water that has been made alkaline by lixiviation of vegetable ashes.
2 any strong alkaline solution, esp. of potassium hydroxide used for washing or cleansing.

Etymology

OE leag f. Gmc: cf. LATHER