Recall army-corps medic with some hesitation (8)
I believe the answer is:
remember
'recall' is the definition.
('remember' can be a synonym of 'recall')
'army-corps medic with some hesitation' is the wordplay.
'army corps' becomes 'reme' (Royal Electrical and Mechanical Engineers).
'medic' becomes 'mb' (Bachelor of Medicine).
'with' means one lot of letters go next to another.
'some hesitation' becomes 'er'.
'reme'+'mb'+'er'='REMEMBER'
(Other definitions for remember that I've seen before include "Don't forget" , "Retain memory of" , "Call to mind" , "Recall from memory" , "Be sure" .)