sensitise has 4 distinct synonyms spread across 4 of its 4 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is desensitise.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
cause to sense; make sensitive
“She sensitized me with respect to gender differences in this traditional male-dominated society”
make sensitive to a drug or allergen
“Long-term exposure to this medicine may sensitize you to the allergen”
Synonyms, antonyms and the broader and narrower relations for sensitise come from Princeton University’s WordNet. Full sources and licences.