lukewarm vs halfhearted

lukewarm and halfhearted both are adjectives.

Word	Noun	Adjective	Verb	Adverb
lukewarm	No	Yes	No	No
halfhearted	No	Yes	No	No

As adjectives, lukewarm and halfhearted are synonyms defined as:

lukewarm and halfhearted: feeling or showing little interest or enthusiasm

Other synonyms of lukewarm include half-hearted, tepid.

lukewarm (adjective)	halfhearted (adjective)
feeling or showing little interest or enthusiasm	feeling or showing little interest or enthusiasm
moderately warm