Open English Wordnet
Adjectives
(s)apathetic, indifferentmarked by a lack of interest“an apathetic audience”, “the universe is neither hostile nor friendly; it is simply indifferent”
(s)indifferentshowing no care or concern in attitude or action“indifferent to the sufferings of others”, “indifferent to her plea”
(s)deaf, indifferent(usually followed by ‘to’) unwilling or refusing to pay heed“deaf to her warnings”
(s)immaterial, indifferent(often followed by ‘to’) lacking importance; not mattering one way or the other“whether you choose to do it or not is a matter that is quite immaterial (or indifferent)”, “what others think is altogether indifferent to him”
(s)indifferentfairly poor to not very good“has an indifferent singing voice”, “has indifferent qualifications for the job”
(s)inert, indifferent, neutralhaving only a limited ability to react chemically; chemically inactive“inert matter”, “an indifferent chemical in a reaction”
(s)indifferentmarked by no especial liking or dislike or preference for one thing over another“indifferent about which book you would give them”, “was indifferent to their acceptance or rejection of her invitation”
(s)indifferent, unbiased, unbiassedcharacterized by a lack of partiality“a properly indifferent jury”, “an unbiased account of her family problems”
(s)indifferent, so-sobeing neither good nor bad“an indifferent performance”, “a gifted painter but an indifferent actor”, “a so-so golfer”, “feeling only so-so”