containerboard

or con·tain·er board

[ kuh n-tey-ner-bawrd, -bohrd ]
/ kənˈteɪ nərˌbɔrd, -ˌboʊrd /

noun

any paperboard used in making containers, as corrugated paper or cardboard.

Origin of containerboard

First recorded in 1920–25; container + board
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019