iritate
pest
It could be a lot of things, but illness could be an answer.
The noun 'mischief' is an abstract noun, a word for conduct or activity that playfully causes petty annoyance; a word for a behavior.
"Annoy" is the verb form of "annoyance".
What is a seven letter word with w as the sixth letter?
Since the letter Y falls at the end of a syllable, it is used as a consonant in this word.
Holiday is a seven letter word.
The word "Pesky" is defined as troublesome and annoying. Therefore a "Pesky Kid" is a child who causes trouble or is an annoyance to others.
What is a seven letter word with o as the sixth letter
Luggage, is a seven letter word for bags.
There are (at least) 7 definitions of the word when used as a noun, one of which is "the devil", but it generally means 'conduct or activity that playfully causes petty annoyance'.
An annoyance is like a pebble in your shoe, constantly causing irritation and discomfort.