IPA: /ʌnˈplɛzəntli/
KK: /ʌnˈplɛzəntli/
In a way that is not pleasant or agreeable; causing discomfort or displeasure.
The weather turned unpleasantly cold, making it hard to enjoy the picnic.
Unpleasantly → It is formed from "un-" (meaning not) and "pleasant" (from Latin "placere", meaning to please) and "-ly" (meaning in a manner). The word "unpleasantly" means in a manner that is not pleasing or agreeable.
Think of 'not' ('un-') being combined with 'pleasing' ('pleasant') to remember that 'unpleasantly' describes something that is not pleasing.