Titter – meaning of the word and example

To laugh nervously, often at something that you feel you should not be laughing at. (Cambridge Dictionary)

If someone titters, they give a short nervous laugh, especially when they are embarrassed about something. (Collins Dictionary)

To laugh in a nervous, affected, or partly suppressed manner: Giggle, snicker. (Merriam – Webster)

Give a short, half-suppressed laugh; giggle. (Oxford Dictionaries)

Example

Titter cartoon and comics.

https://www.cartoonstock.com/directory/t/titter.asp