Gosh, what a blimpish exclamation! (3)
I believe the answer is:
gad
'exclamation' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for gad that I've seen before include "Move about freely" , "biblical tribe" , "carefree adventure" , "Gallivant in search of pleasure" , "country of old" .)