Timidity of head following fling (7)
I believe the answer is:
shyness
'timidity' is the definition.
(shyness is a kind of timidity)
'head following fling' is the wordplay.
'head' becomes 'ness' (ness is a headland).
'following' means one lot of letters go next to another.
'fling' becomes 'shy' (I've seen this before).
'ness' after 'shy' is 'SHYNESS'.
'of' is the link.
(Other definitions for shyness that I've seen before include "Retiring quality" , "lack of confidence" , "Bashful nature" , "Modesty, reticence" , "Reserve" .)