by board (adjective) down the drain: unrecoverable
Sinonime: assembly,
basis,
bed,
box, chassis, core, corpus,
crux,
essence,
frame, fuselage,
gist, gravamen, groundwork, hull, main part,
majority, mass,
material,
matter, pith, skeleton, staple, substance, substructure,
sum,
tenor,
total, trunk, whole
Antonime: nothing, nothingness