IPA: //ˌʌn.kənˈdʒiː.njəl//
KK: /ʌnˈkɒn.dʒi.əl/
Not suitable or pleasant; not friendly or agreeable in nature.
The atmosphere at the party was uncongenial, making it hard for anyone to enjoy themselves.
Uncongenial → It is formed from "un-" (meaning not) and "congenial" (from Latin "congenialis", meaning suitable or agreeable). The word "uncongenial" means not suitable or agreeable, often referring to a person or environment that is unfriendly or incompatible.
Think of 'not' ('un-') being combined with 'agreeable' ('congenial') — that's why uncongenial describes something that is not friendly or suitable.