Informal One that is small or insignificant.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "pip-squeak" in a sentence
"Ryan Phillipe is a pip-squeak bro who should not even remotely be in the running."
"But Deanna is such a pip-squeak, the leggings barely stretch over my calves, even with Deanna holding the waist and me trying to bounce my way into them."
"Why should I be afraid of the pip-squeak you quote?"