Kinktionary
More like guidelines and a lot less like definitions.
Tickling
Tickling is a form of sensation play where someone's body is touched in a way that causes involuntary recoil or laughter. The person providing the ticking sensation is known at the tickle top or tickler (often referred to as the "Ler") , whereas the person receiving the sensation is known as the tickle bottom or ticklee (often referred to as the "Lee").
Types of Tickling
There are two general types of tickling sensation: 1. Light tickling, also known as knismesis, which provides a sensation similar to an insect crawling across the skin. It typically does not cause laughter. Some people find it annoying, but it can also be pleasurable (particularly in an erotic context). 2. Heavy tickling, also known as gargalesis, results from a deeper pressure, and generally induces laughing.
One common type of tickle play is tickle torture. Tickling can be a very intense experience for the ticklee, and a tickle session is often extended to test the "endurance" of the ticklee. Such a scene may include elements of role play, eg. the tickler takes on the role of an "interrogator" trying to extract information from a "prisoner".
Ways to Play
Tickling is often done with the fingers and fingernails, but tools such as feathers and brushes can also be used. Oils are sometimes applied to the skin in order to increase the tickling sensation.
Tickling is often combined with bondage. There is a strong psychological component to tickling, and the more helpless and vulnerable the ticklee feels, the stronger their response will be to being tickled.