I run up and check PIN (5)
I believe the answer is:
rivet
'pin' is the definition.
(I know that rivet is a type of pin)
'i run up and check' is the wordplay.
'run' becomes 'r' (cricket abbreviation).
'up' is a reversal indicator (in down clue: letters go upwards).
'and' means one lot of letters go next to another.
'check' becomes 'vet' (I've seen this in other clues).
'i'+'r'='ir'
'ir' reversed gives 'ri'.
'ri'+'vet'='RIVET'
(Other definitions for rivet that I've seen before include "Heavy fastening pin with head and hammered end" , "Trevi (anag.)" , "Short metal fastener" , "Transfix" , "Bolt in iron" .)