Rushed to meet head of KGB in station (4)
I believe the answer is:
rank
'station' is the definition.
(I've seen this in another clue)
'rushed to meet head of kgb' is the wordplay.
'rushed' becomes 'ran'.
'to meet' is a charade indicator (letters next to each other).
'head of' says to take the initial letters.
The initial letter of 'kgb' is 'k'.
'ran'+'k'='RANK'
'in' is the link.
(Other definitions for rank that I've seen before include "Excessive" , "The military row is coarsely overgrown" , "Relative status" , "Row of people standing abreast" , "Status, grade" .)