Ship’s rope in dock holding beam up (7)
I believe the answer is:
lanyard
'ship's rope' is the definition.
(I've seen this in another clue)
'dock holding beam up' is the wordplay.
'dock' becomes 'land' (both can mean to arrive on dry land).
'holding' indicates putting letters inside.
'beam' becomes 'ray' (synonyms).
'up' is a reversal indicator (in down clue: letters go upwards).
'ray' reversed gives 'yar'.
'land' going around 'yar' is 'LANYARD'.
'in' is the link.
(Other definitions for lanyard that I've seen before include "Rope on ship's rigging" , "Line for extending or fastening ship's rigging" , "Cord worn around the neck by Boy Scout" , "Short rope used as a fastening" , "Ribbon or cord around neck" .)