Marched round gateway (4)
I believe the answer is:
arch
'gateway' is the definition.
(I've seen this before)
'marched round' is the wordplay.
'ARCH' is hidden in amongst the letters.
However, I am uncertain how the hidden word is indicated.
Can you help me to learn more?
(Other definitions for arch that I've seen before include "Char the curved structure" , "Curved bony structure in the foot" , "Curvature" , "Chief; bow" , "Curved span" .)