1. manifesting partiality

e.g. a discriminatory tax
preferential tariff rates
preferential treatment
a preferential shop gives priority or advantage to union members in hiring or promoting

Synonym: preferential

2. being biased or having a belief or attitude formed beforehand

e.g. a prejudiced judge

Synonym: prejudiced

3. capable of making fine distinctions

Synonym: discriminative

4. containing or implying a slight or showing prejudice

e.g. discriminatory attitudes and practices
invidious comparisons

Synonym: invidious