Splendid joke I found in computer (8)
I believe the answer is:
majestic
'splendid' is the definition.
(thesaurus)
'joke i found in computer' is the wordplay.
'joke' becomes 'jest' ('jest' can be a synonym of 'joke'**).
'found in' means one lot of letters goes inside another.
'computer' becomes 'mac' (I've seen this before).
'jest'+'i'='jesti'
'jesti' put inside 'mac' is 'MAJESTIC'.
(Other definitions for majestic that I've seen before include "Stately; sublime" , "Impressively beautiful" , "Of noble bearing, like a king" , "Splendid, regal" , "Of royal appearance or status" .)