Standing very clear -- it's exploding (8)
I believe the answer is:
vertical
'standing' is the definition.
(thesaurus)
'very clear it's exploding' is the wordplay.
'very' becomes 'v' (abbreviation).
'exploding' is an anagram indicator.
'clear'+'it'='clearit'
'clearit' with letters rearranged gives 'ertical'.
'v'+'ertical'='VERTICAL'
(Other definitions for vertical that I've seen before include "At right angles to the base line" , "Not laid down" , "Absolutely upright" , "Perfectly upright" , "Straight up" .)