IPA: /ˌʌn.rɪˈlaɪ.ə.bli/
KK: /ʌnˈrɛlaɪəbli/
In a way that cannot be trusted or depended on.
The train arrived unreliably, causing many passengers to miss their connections.
Unreliably → It is formed from "un-" (meaning not) and "rely" (from Latin "religere", meaning to bind or trust) and "-ably" (meaning in a manner). The word "unreliably" means in a manner that is not trustworthy or dependable.
Think of 'not' ('un-') being added to 'rely' which means to trust, and the '-ably' shows how something is done. This helps you remember that 'unreliably' means not being trustworthy.