having no interest or opinion; neither for nor against

unfeeling, uninterested

paying no attention to; regardless of (which is more usual)

without regard

(appearing) tired, unenthusiastic

careless, indifferent

too tired to show interest or do anything

spiritless, without energy

giving no thought or care to something; not having or not requiring intelligence; not having a purpose

oblivious, stupid; automatic

taking too little care; guilty of neglect

careless, indifferent

unaware, having no memory, (of something)

unaware, ignorant

done as a duty or routine but without care, sincerely or interest

automatic, unthinking

so deep in thought, so carried away by feelings, that one is unaware of other things

absorbed, fascinated

not thinking or caring about the effects, consequences

irresponsible in thought, deed

paying no attention to a person or thing

indifferent, unconcerned

careless; negligent

careless, thoughtless

lazy (the usual word)

lazy

careless and untidy; (of clothes) loose and fitting badly; foolishly sentimental; weakly emotional

messy

of or on the surface only; not thorough or deep

without depth, detail

not thinking; selfish; inconsiderate

inconsiderate

not aware

ignorant

not anxious (about); not (emotionally) concerned (with)

carefree; apathetic

(especially) not having, made without, adequate information

unaware

unaware of something

not aware or attentive

not quick at noticing things

not observant

not social; outside the usual working day

unfeeling, uninterested