Come to a stop in lake in Panama, say (4)
I believe the answer is:
halt
'come to a stop' is the definition.
(I've seen this in another clue)
'lake in panama say' is the wordplay.
'lake' becomes 'L' (geographical abbreviation).
'in' is an insertion indicator.
'panama say' becomes 'hat' (Panama is a type of hat).
'l' going within 'hat' is 'HALT'.
'in' is the link.
(Other definitions for halt that I've seen before include "Limp; minor station" , "Bring to a stop; lame" , "Falter - stop" , "Stop or pause" , "Stop; minor station" .)