IPA: //ʌn.kəmˈpæʃ.ən.ət//
KK: /ʌnˌkəmˈpæʃənɪt/
Lacking sympathy or kindness towards others; not showing compassion.
His uncompassionate attitude made it difficult for others to approach him for help.
Uncompassionate → It is formed from "un-" (meaning not) and "compassion" (from Latin "compassio", meaning to suffer with). The word "uncompassionate" means not showing compassion or empathy towards others.
Think of 'not' ('un-') feeling 'with' someone in their suffering ('compassio') — that's why uncompassionate means lacking empathy.