Clock feature (5)
(Other definitions for dial that I've seen before include "Indicator" , "feature of old phone?" , "Laid up like clock-face" , "Select a telephone number" , "Ring the clock-face" .)
'clock feature' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for alarm that I've seen before include "Frighten, scare" , "Device to signal danger" , "Flap" , "Warning siren" , "Warning sound/device" .)