Origin of the word "LUKEWARM"

[system]

The word is old indeed. Quoth www.m-w.com:

Main Entry: luke·warm
Pronunciation: 'lük-'worm
Function: adjective
Etymology: Middle English, from luke lukewarm + warm; probably akin to Old High German lAo lukewarm – more at LEE
Date: 14th century
1 : moderately warm : TEPID
2 : lacking conviction : HALFHEARTED

• luke·warm·ly adverb
• luke·warm·ness noun

(my emphasis). Some more pointers:
http://www.randomhouse.com/jesse/?date=19970512
http://www.greenapple.com/~words1/back-f2.html#lukewarm

Holger