The instructions said to use lukewarm water, and Kim, being a linguist, wondered about the luke of lukewarm; we don’t, after all, have luke + anything else, even lukecool, lukecold, or lukehot. I said that she wasn’t going to be satisfied with the standard story, and she wasn’t. A brief version, from NOAD2:
(of liquid or food that should be hot) only moderately warm; tepid. ORIGIN late Middle English: from dialect luke (probably from dialect lew ‘lukewarm’ and related to lee [‘shelter from wind or weather’]) + warm
This account is suppositious, and unclear on many points (what dialects, how, and why? and is lukewarm really etymologically ‘lukewarm’ + warm?). So it occurred to us to just invent more satisfying etymologies — or, better, to invite others to invent them, to devise etymythologies. This is that invitation: to suggest better stories than the truth (as far as we know the truth), IN A COMMENT ON THIS BLOG (I will disregard e-mail to me or Kim and comments on Facebook or Google+ or ADS-L or wherever else; I cannot possibly spend time amalgamating suggestions from half a dozen sources). But before you jump in, read the rest of what I have to say about lukewarm and about etymythology. And, eventually, some suggestions as to what you might use to play with for ideas about lukewarm etymythologies.