Lukewarm

This word meaning moderately warm, both literally and figuratively, dates from the 1400s when the suffix warm was added to a now obsolete Middle English word leuk meaning mild or moderate, which in turn derives from earlier Old Norse meaning the same thing. Still in existence, but rarely encountered these days, is the word lew which means warm or sheltered from the wind which derives from the same source. From the 1600s, this evolved into its more common form of lee, which is still very much in use in words like leeward.