Sufficient space to tie a ship up (4)

I believe the answer is:

room

I'm a little stuck... Click here to teach me more about this clue!

'sufficient space' is the definition.
(I've seen this in another clue)

I don't understand the remainder of the clue.

(Other definitions for room that I've seen before include "See 1" , "Space (for elbows?)" , "Space; part of building" , "Box ---, storage area" , "Scope; living space" .)

I've seen this clue in The Globe and Mail.

Want a hint initially instead of a full solution? Install my app