IPA: /ˌʌn.rɪˈkɔːr.dɪd/
KK: /ʌnˈrɪkɔrdɪd/
Something that has not been documented or noted down.
The unrecorded data may lead to inaccurate conclusions.
Unrecorded → It is formed from "un-" (meaning not) and "record" (from Latin "recordari", meaning to remember or to recall) and "-ed" (a suffix indicating the past participle). The word "unrecorded" means not remembered or not documented.
Think of 'not' ('un-') remembering something ('record') — that's why unrecorded means something that hasn't been documented.