One runs up back street and bursts in (7)
I believe the answer is:
irrupts
'and bursts in' is the definition.
I can't tell whether this defines the answer.
'one runs up back street' is the wordplay.
'one' becomes 'i' (Roman numeral).
'runs' becomes 'rr' (r is abbreviation for run in cricket, twice).
'back' is a reversal indicator.
'street' becomes 'st' (abbreviation).
'st' back-to-front is 'ts'.
'i'+'rr'+'up'+'ts'='IRRUPTS'
Can you help me to learn more?
(Other definitions for irrupts that I've seen before include "Makes a sudden entry or invasion" , "Bursts into, enters forcibly" , "Stirrup? (anag)" , "Breaks in" .)