The phrase "old crayons" refers to crayons that are not new anymore. It means crayons that have been used a lot and are no longer in their original condition or shape.
Sentences with «old crayons»
Submitted by Theresa M. Santiago Students melt old crayon stubs and mold them into interesting shapes and characters. (educationworld.com)
Zakka Life has a tutorial on how to recycle old crayons into new crayons using candy molds. (crunchydomesticgoddess.com)
Recycle old crayons into colorful new ones. (thespruce.com)