IPA: /ʌnˈæm.bɪ.ʃəs/
KK: /ʌnˈæmbɪʃəs/
Not having a strong desire to succeed or achieve goals.
He is unambitious and prefers a quiet life without much competition.
Unambitious → It is formed from "un-" (meaning not) and "ambitious" (from Latin "ambitiosus", meaning eager for advancement or fame). The word "unambitious" means not eager for advancement or lacking ambition.
Think of 'not' ('un-') being added to 'eager for advancement' ('ambitious') — that's why unambitious means lacking that eagerness.