____ code (4)
'code' is the definition.
(Morse code)
This is the entire clue.
(Other definitions for morse that I've seen before include "One who enjoyed solving code" , "used to transmit messages" , "Endeavour" , "Kind of code" , "Oxford detective" .)
'code' is the definition.
(area code is a kind of code)
This is the entire clue.
(Other definitions for area that I've seen before include "Extent of a 2-dimensional surface" , "Field of activity or surface" , "field of study" , "environs" , "Speaking formally to (someone)" .)
'code' is the definition.
(I know that ZIP is a type of code)
This is the entire clue.
(Other definitions for zip that I've seen before include "tear" , "Fastening device" , "Compress file for storage on disk < (or flash" , "Sound of bullet passing" , "Type of fastener" .)