Profundity shown by a department head initially! (5)
I believe the answer is:
depth
'profundity' is the definition.
(I've seen this before)
'shown by a department head initially' is the wordplay.
'shown by' is a charade indicator (letters next to each other).
'a department' becomes 'dept'.
'initially' says to take the initial letters.
The initial letter of 'head' is 'h'.
'dept'+'h' is 'DEPTH'.
(Other definitions for depth that I've seen before include "Distance from the surface to the bottom" , "Distance downwards" , "Intensity (of emotion)" , "Military life; vulgarly artificial" , "Intensity; profundity" .)