Launched reference work about writer (6)
I believe the answer is:
opened
'launched' is the definition.
The answer and definition can be both related to change as well as being past participle verbs.
Maybe there's an association between them I don't understand?
'reference work about writer' is the wordplay.
'reference work' becomes 'OED'.
'about' is an insertion indicator.
'writer' becomes 'pen' (something which writes).
'oed' going around 'pen' is 'OPENED'.
Can you help me to learn more?
(Other definitions for opened that I've seen before include "Unlocked or unfolded" , "Started, a meeting say" , "Turned the key, facilitated entry" , "Gave access using key" , "starting the game" .)