Sillies are the funny or silly thoughts or actions that make you laugh.
Sillies are usually good because they make people happy and laugh.
Examples:
She has the sillies and can't stop laughing.
The children always get the sillies before bedtime.
When I feel sad, I try to think of sillies to make me happy.
The dog chasing its tail always gives me the sillies.
The sillies took over and everyone laughed and laughed.
The sillies are like little tickles in your brain.