I couldn't find
knismesis in any dictionary other than Wiktionary, even though the word was coined over 100 years ago. This might suggest it's too obscure and technical for us. But in fact it describes a very familiar phenomenon, so perhaps it ought to be more widely known.
In 1897 two psychologists proposed the terms
gargalesis and
knismesis, for two types of tickling.
Gargalesis causes laughter, whereas
knismesis is a very light tickling, such as you might feel from a bug walking across your skin. Though these words are certainly not in wide use, they have occasionally made it into mass circulation publications, such as the
Daily Mail, which in 2016 carried an article on the theme "Why CAN'T you tickle yourself?":
There are actually two types of tickles: knismesis and gargalesis. The former is associated with low levels of stimulation to sensitive parts of the body, and can be triggered by a light touch or by a light electric current.
Knismesis can also be triggered by crawling insects or parasites, prompting scratching or rubbing at the ticklish spot, thereby removing the pest...
Gargalesis refers to harder, laughter-inducing tickling, and involves the repeated application of high pressure to sensitive areas.
The word also appeared in a 2009 novel,
The Puppy Bomb: A Jonah LeClaire Detective Mystery, by James Lynch:
Knismesis is the other type of tickling, with no laughter, like a bug crawling up your leg. It's easy to remember words in pairs—gargalesis and knismesis, or flotsam and jetsam—driftwood floating in the creek versus a beer can deliberately thrown into the creek.
I'll add
knismesis as a rare word, along with its counterpart,
gargalesis.