Commemoration: what about inscribing it in gibberish? (7)
I believe the answer is:
epitaph
'commemoration' is the definition.
(epitaph is a kind of commemoration)
I can't explain the rest of the clue.
(Other definitions for epitaph that I've seen before include "Statement of commemoration for a dead person" , "Gravestone inscription" , "Memorial inscription" , "Memorial words" , "Tombstone inscription" .)