Eat rapidly (5)
(Other definitions for scoff that I've seen before include "Speak scornfully; eat" , "Deride - guzzle" , "Furiously swallow" , "Quickly swallow" , "taunt" .)
(Other definitions for inhale that I've seen before include "Whiff" , "Breathe in (gas, smoke)" , "take the air" , "Draw breath" , "Take smoke into the lungs" .)