So hesitantly give dismissal (4)
I believe the answer is:
ergo
'so' is the definition.
('ergo' can be a synonym of 'so')
'hesitantly give dismissal' is the wordplay.
'hesitantly' becomes 'er' (I've seen this in other clues).
'give dismissal' becomes 'go' (I can't explain this - if you can you should give a lot more credence to this answer).
'er'+'go'='ERGO'
(Other definitions for ergo that I've seen before include "Hence" , "Therefore - what a goer" , "'Cogito, ---- sum'" , "Consequently" , "'Therefore, to the old Romans (4)'" .)