Securing runs, I thump ground in victory (7)
I believe the answer is:
triumph
'victory' is the definition.
('triumph' can be a synonym of 'victory')
'securing runs i thump ground' is the wordplay.
'securing' indicates putting letters inside.
'runs' becomes 'r' (cricket abbreviation).
'ground' is an anagram indicator (grind the letters ).
'i'+'thump'='ithump'
'ithump' is an anagram of 'tiumph'.
'r' inserted inside 'tiumph' is 'TRIUMPH'.
'in' is the link.
(Other definitions for triumph that I've seen before include "The exultation of victory" , "Conquer, prevail" , "Crow" , "Victory, win" , "hit" .)