A lot died with gas all around (2,3)
I believe the answer is:
no end
'a lot' is the definition.
(I've seen this in another clue)
'died with gas all around' is the wordplay.
'died' becomes 'd' (abbreviation next to the year of someone's death).
'with' means one lot of letters go next to another.
'gas' becomes 'neon' (neon is a gas).
'all around' says the letters should be written in reverse.
'd'+'neon'='dneon'
'dneon' backwards is 'NO END'.
(Other definitions for no end that I've seen before include "Very much (colloq.)" , "Without limit" , "goalless?" , "Non-stop" , "A lot" .)