Garbled notice inscribed with second digital symbol (8)
I believe the answer is:
emoticon
'digital symbol' is the definition.
(symbol used in digital communication)
'garbled notice inscribed with second' is the wordplay.
'garbled' indicates anagramming the letters.
'inscribed with' means one lot of letters goes inside another (I've seen this in other clues).
'second' becomes 'mo' (both are short periods of time).
'notice' is an anagram of 'eticon'.
'eticon' enclosing 'mo' is 'EMOTICON'.
(Other definitions for emoticon that I've seen before include "Representation of a facial expression in electronic messages" , "smiley, perhaps?" , "Moody characters" , "Graphic way of conveying feeling in e-mails" , "Mince too (anag.)" .)