Dive steeply (6)
I believe the answer is:
plunge
(Other definitions for plunge that I've seen before include "Thrust into liquid" , "Nose-dive" , "Fall suddenly and uncontrollably" , "A steep drop" , "Take the . . . . . . - dive right in" .)
I believe the answer is:
plunge
(Other definitions for plunge that I've seen before include "Thrust into liquid" , "Nose-dive" , "Fall suddenly and uncontrollably" , "A steep drop" , "Take the . . . . . . - dive right in" .)