pesky
adj. B2 Upper Intermediate US //ˈpɛski// UK //pˈɛski// pesky
adj. describes something that is annoying or causes small problems over and over again. It is often used for things that are hard to get rid of, like insects or a cough.
adj. causing irritation or annoyance; troublesome in a persistent but relatively minor way. Often used with a lighthearted or mildly frustrated tone.
I finally caught that pesky fly in the kitchen.
The gardener spent all morning trying to remove those pesky weeds from the flower beds.
Despite the software's impressive capabilities, a few pesky bugs in the user interface continue to frustrate early adopters and hinder a full commercial release.
Possibly from pesty. Compare similar alteration between nasty and nasky.
Usage
Typically used attributively before the noun it modifies.