Lav and toilet endlessly turned explosive (8)
I believe the answer is:
volatile
'explosive' is the definition.
('volatile' can be similar in meaning to 'explosive')
'lav and toilet endlessly turned' is the wordplay.
'and' says to put letters next to each other (I've seen this in other clues).
'endlessly' means to remove the last letter.
'turned' indicates an anagram.
'toilet' with its final letter taken off is 'toile'.
'lav' after 'toile' is 'toilelav'.
'toilelav' with letters rearranged gives 'VOLATILE'.
(Other definitions for volatile that I've seen before include "Fickle; tending to vaporise" , "Explosive or excitable" , "Easily vaporised" , "Disposed to sudden changes" , "Liable to change rapidly and unpredictably" .)