Premier opened new library yesterday, and nothing more (4)
I believe the answer is:
only
This clue could be a double definition.
'premier opened new library yesterday' is the first definition.
'only' can be an answer for 'yesterday' (thesaurus). I am not sure about the 'premier opened new library' bit.
'and nothing more' is the second definition.
(I've seen this before)
Can you help me to learn more?
(Other definitions for only that I've seen before include "See 6" , "Exclusive - individual" , "Single, solitary" , "And no one else" , "Existing alone with no other, perhaps a child" .)