idiosyncratic

adjective

each researcher had his or her own idiosyncratic interest |

some might think this a rather idiosyncratic approach:

distinctive, individual, characteristic, distinct, distinguishing, peculiar, individualistic, different, typical, special, specific, representative, unique, personal, private, essential;

eccentric, unconventional, uncommon, abnormal, irregular, aberrant, anomalous, odd, off-center, quirky, queer, strange, weird, bizarre, outlandish, freakish, extraordinary;

rare singular.