Dynamic person with grand in bank (5)
I believe the answer is:
tiger
'dynamic person' is the definition.
(tiger can mean an ambitious or dynamic person)
'grand in bank' is the wordplay.
'grand' becomes 'g' (G is short for grand as in a thousand).
'in' is an insertion indicator.
'bank' becomes 'tier' (both can mean a row of similar things).
'g' going within 'tier' is 'TIGER'.
'with' is the link.
(Other definitions for tiger that I've seen before include "Large wild cat" , "Large cat with black stripes" , "The Celtic one has died" , "dynamic economy" , "Asian animal" .)