Writer invested in dictionary as on first night? (6)
I believe the answer is:
opened
'writer invested in dictionary as on first night?' is the definition.
I can't tell whether this defines the answer.
'writer invested in dictionary' is the wordplay.
'writer' becomes 'pen' (something which writes).
'invested in' means one lot of letters goes inside another.
'dictionary' becomes 'OED' (Oxford English Dictionary).
'pen' put inside 'oed' is 'OPENED'.
Can you help me to learn more?
(Other definitions for opened that I've seen before include "Started, a meeting say" , "Began - undone" , "starting the game" , "Unfastened or removed a barrier" , "Unfastened or moved a barrier" .)