Argon vapour very much behind source of some marine obstruction (8)
I believe the answer is:
sargasso
'marine obstruction' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'argon vapour very much behind source of some' is the wordplay.
'argon' becomes 'Ar' (Ar is the chemical symbol for argon).
'vapour' becomes 'gas' (I've seen this before).
'very much' becomes 'so' (so can mean very much or extremely).
'behind' says to put letters next to each other.
'of some' says to take the initial letters (I've seen 'some' mean this).
The initial letter of 'source' is 's'.
'ar'+'gas'+'so'='argasso'
'argasso' after 's' is 'SARGASSO'.
Can you help me to learn more?
(Other definitions for sargasso that I've seen before include "Sea known for seaweed" , "Seaweed giving name to a sea" , "Gas soars around the North Atlantic sea" , "Mass of weed" , "'Sea in the North Atlantic, the only sea without shores (8)'" .)