IPA: /ˌʌn.rɪˈviːld/
KK: /ʌnˈriːviːld/
Something that has not been shown or made known; it is kept hidden or secret.
The unrevealed details of the plan kept everyone guessing.
Unrevealed → It is formed from "un-" (meaning not) and "revealed" (from Latin "revelare", meaning to unveil or disclose). The word "unrevealed" means not disclosed or not made known.
Think of 'not' ('un-') making something 'unveiled' or 'not disclosed' — that's what unrevealed means.