IPA: /ˌʌn.dɪsˈtɜːrbd/
KK: /ʌnˈdɪstɜrbd/
Not affected or interrupted; remaining in a peaceful or quiet state.
The forest was undisturbed, allowing wildlife to thrive.
Undisturbed → It is formed from "un-" (meaning not) and "disturb" (from Latin "disturbare", meaning to throw into disorder). The word "undisturbed" means not thrown into disorder or remaining in a state of calm.
Think of 'not' ('un-') being added to 'disturb' — this helps you remember that 'undisturbed' means remaining calm and in order.