Leapt from rear of bus before crash (6)
I believe the answer is:
sprang
'leapt' is the definition.
(springing is a kind of leaping)
'rear of bus before crash' is the wordplay.
'rear of bus' becomes 's' (I am not sure about this - if you are sure you should believe this answer much more).
'before' says to put letters next to each other.
'crash' becomes 'prang' (I've seen this before).
's'+'prang'='SPRANG'
'from' is the link.
Can you help me to learn more?
(Other definitions for sprang that I've seen before include "Suddenly leapt (up)" , "Leapt foward" , "suddenly developed" , "Jumped or leaped in single movement (6(" , "Lept forward" .)