task
A four letter word meaning the foundation of something is base.
papa
asea
dumb
taxi
A two-by-four is a heavy piece of wood, so I presume that the expression means to hit them hard.
task
The four letter word that means, "I forbid," is veto.veto
data
chip
The four letter word is dawn.
aria aida
song
Lump
A lump
slab
Chip