Intend a vessel to go round a little lake (4)
I believe the answer is:
plan
'intend' is the definition.
(planning is a kind of intending)
'a vessel to go round a little lake' is the wordplay.
'a vessel' becomes 'pan' (vessel or container for cooking).
'to go round' is an insertion indicator.
'a little' says to take the initial letters.
The first letter of 'lake' is 'l'.
'pan' going around 'l' is 'PLAN'.
(Other definitions for plan that I've seen before include "Map; intention" , "Scheme, design" , "Formulate" , "Scale drawing of a structure" , "Blueprint" .)