formboard

[ fawrm-bawrd, -bohrd ]
/ ˈfɔrmˌbɔrd, -ˌboʊrd /

noun

a board or slab serving as a form for poured concrete.

Origin of formboard

First recorded in 1955–60; form + board
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019