unenthusiastic (adj.)

• apathetic
• backward
• balking
• balky
• blase
• cold
• cool
• dilatory
• grudging
• halfhearted
• indifferent
• laggard
• loath
• loveless
• lukewarm
• passionless
• perfunctory
• reluctant
• restive
• slow
• un-come-at-able
• unambitious
• unapproachable
• unattainable
• undesirous
• uneager
• unexcited
• ungetatable
• unimpressed
• uninterested
• unobtainable
• unreachable
• unresponsive