First a thumbs down then a thumbs up, from the corner (4)
I believe the answer is:
nook
'the corner' is the definition.
(synonyms)
'first a thumbs down then a thumbs up' is the wordplay.
'first' says to put letters next to each other.
'a thumbs' becomes 'noo' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'down' suggests deleting specific letters ('down' can mean missing).
'then' becomes 'so' (both can mean 'therefore' or 'in that case').
'a thumbs up' becomes 'oks' (I've seen this in another clue).
'oks' with 'so' removed is 'k'.
'noo'+'k' is 'NOOK'.
'from' acts as a link.
Can you help me to learn more?
(Other definitions for nook that I've seen before include "Corner - narrow recess" , "Recess offering seclusion" , "Cosy corner" , "Small space" , "Secluded corner" .)