IPA: /ˌʌn.rɪˈzɜːrvd/
KK: /ʌnˈrɛzərvd/
Showing complete openness and honesty without holding back any feelings or opinions.
She gave an unreserved compliment about his performance.
Unreserved → It is formed from "un-" (meaning not) and "reserved" (from Latin "reservare", meaning to keep back or hold). The word "unreserved" means not held back or freely given without reservation.
Think of 'not' ('un-') holding back or keeping something ('reserved') — that's why unreserved means freely given.