IPA: /ˌʌn.dɪsˈɡaɪzd.li/
KK: /ʌnˈdɪsɡaɪzdli/
In a way that is open and not hidden; clearly showing one's thoughts or feelings without any attempt to conceal them.
She expressed her feelings undisguisedly, making it clear how she truly felt about the situation.
Undisguisedly → It is formed from "un-" (meaning not), "disguise" (from Old French *desguiser*, meaning to conceal or hide), and "-edly" (a suffix forming adverbs). The word means not concealed or hidden, presenting oneself openly and honestly.
Think of 'not' ('un-') hiding or concealing ('disguise') something — that's why undisguisedly means to present oneself openly.