Dull pain landing Charlie and Henry in AE (4)
I believe the answer is:
ache
'dull pain' is the definition.
(I've seen this before)
'charlie and henry in ae' is the wordplay.
'charlie' becomes 'C' (phonetic alphabet: alpha, bravo, charlie etc.).
'and' means one lot of letters go next to another.
'henry' becomes 'H' (symbol for the unit of electrical inductance).
'in' means one lot of letters goes inside another.
'c'+'h'='ch'
'ch' going into 'ae' is 'ACHE'.
'landing' is the link.
(Other definitions for ache that I've seen before include "Cause pain" , "Hanker" , "Suffer dull pain" , "A dull lingering pain" , "burn" .)