The phrase "breathable mesh" means a fabric or material that allows air and moisture to pass through easily, making it comfortable to wear or use. Full definition
This inclined sleeper has an extra deep seat with breathable mesh sides. (mommystroller.com)
It features two breathable mesh panels on either side of the canopy. (earlymomentsmatter.org)
With breathable mesh sides, your baby will have plenty of air flow and you'll be able to peek in on your child at any time with no trouble. (abckidsinc.com)