(archaic, now only humorous or dialectal) Food, provender.
And tho' knights errant, as some think, / Of old did neither eat nor drink, / Because when thorough deserts vast, / And regions desolate, they past, / Where belly-timber above ground, / Or under, was not to be found …
The strength of every other member / Is founded on your belly-timber; / The qualms or raptures of your blood, / Rise in proportion to your food; …