Which word refers to lightness of manner or frivolity?

The correct answer, levity, specifically refers to a lightness of manner or the quality of being frivolous or unserious. This term is often used to describe a situation characterized by a lack of seriousness, where humor and light-heartedness dominate the behavior or atmosphere. Levity can be seen in social interactions where individuals engage in playful banter or jokes, creating a joyful and relaxed environment.

The other terms do not convey this specific meaning. Intractable refers to something that is difficult to manage or control. Inundate means to overwhelm or flood, typically with water or information. Intolerable describes something that is unbearable or unacceptable. Each of these words encompasses very different attributes and does not connect to the concept of lightness in manner or frivolity.