Economy essentially obliterated by onset of recession in huge dip (7)
I believe the answer is:
immerse
'dip' is the definition.
(thesaurus)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for immerse that I've seen before include "Involve deeply" , "Dunk" , "dive" , "Drown" , "Cover with water, dip into" .)