Heal
The four letter word that means, "I forbid," is veto.veto
The four letter word is dawn.
The four stages of recovery after a collision are acute phase (immediate response to injury), sub-acute phase (continued healing and recovery), rehabilitation phase (regaining strength and function), and reconditioning phase (returning to regular activities and preventing future injury).
Exit
fern
A four letter word meaning the foundation of something is base.
aide
Fast
step
asea
Talk.
papa