1. A short, high-pitched, spasmodic laugh: Trudy had an attack of the giggles after hearing how her friend got lost on his way to visit her.
2. A quiet laugh that is sometimes involuntary in a way that is characteristic of children: The people in the house could hear the giggles of the children who were playing in the back yard.

1. To laugh with repeated short, high pitched, spasmodic sounds; especially, in a childish way, often at something silly: Harry's girlfriend giggled just like a little kid.
2. To laugh audibly with convulsive sounds, but not loudly, sometimes without meaning to or because of nervousness: Several people were all joking and giggling nervously as they were waiting for the ceremony to begin.