something appropriate only for children.
something very easy or simple.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use kid stuff in a sentence
Throughout the 1950s and ’60s, monster movies were largely seen as kid stuff.
Deconstruction is kid stuff—this one delves deep into the psychology behind the universal need to confront evil.
Helen, honey—Tim knows that wishing when you blow out the candles is kid stuff.The Short Life | Francis Donovan
The only time I played football it was just kid stuff, and we wore whatever we had.Center Rush Rowland | Ralph Henry Barbour
Other Idioms and Phrases with kid stuff
Something very easy or uncomplicated, as in That new computer program is kid stuff. This usage alludes to something suitable for young children, or “kids.” [c. 1920]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.