lukewarm vs half-hearted

lukewarm and half-hearted both are adjectives.

Word	Noun	Adjective	Verb	Adverb
lukewarm	No	Yes	No	No
half-hearted	No	Yes	No	No

As adjectives, lukewarm and half-hearted are synonyms defined as:

lukewarm and half-hearted: feeling or showing little interest or enthusiasm

Other synonyms of lukewarm include halfhearted, tepid.

lukewarm (adjective)	half-hearted (adjective)
feeling or showing little interest or enthusiasm	feeling or showing little interest or enthusiasm
moderately warm