IPA: /ʌnˈpɒpjʊləti/
KK: /ʌnˈpɑːpjulərti/
The state of not being liked or accepted by many people.
His unpopularity in school made him feel lonely.
Unpopularity → It is formed from "un-" (meaning not) and "popularity" (from Latin "popularis", meaning of the people). The word "unpopularity" means the state of not being liked or favored by people.
Think of 'not' ('un-') being liked by 'the people' ('popularis') — that's why unpopularity means not being favored.