Lukewarm, a. — Webster enters it under “lukewarm”
Etymology: [See Luke.]
Moderately warm; neither cold nor hot; tepid; not ardent; not zealous; cool; indifferent. " Lukewarm blood." Spenser. " Lukewarm patriots." Addison. An obedience so lukewarm and languishing that it merits not the name of passion. Dryden. -- Luce"warm`ly, adv. -- Luce"warm`ness, n.
Shades of meaning
Fernald lists lukewarmness only as an antonym, under enthusiasm.
He lists it without comment; the entries above explain its neighbors.
Synonyms
none given