Embargo placed on almost entire stock (5)
I believe the answer is:
banal
'stock' is the definition.
(I know that stock can be written as banal)
'embargo placed on almost entire' is the wordplay.
'embargo' becomes 'ban' (I've seen this before).
'placed on' says to put letters next to each other.
'almost' means to remove the last letter (most of the word but not all of it).
'entire' becomes 'all' (I've seen this in another clue).
'all' with its final letter taken away is 'al'.
'ban'+'al'='BANAL'
(Other definitions for banal that I've seen before include "Ordinary and uninteresting" , "Uninteresting, commonplace" , "Obvious and dull" , "Boring or trivial" , "boringly dull" .)