Information from nerd put back on shelf (9)
I believe the answer is:
knowledge
'information' is the definition.
(I've seen this before)
'nerd put back on shelf' is the wordplay.
'nerd' becomes 'wonk' (synonyms).
'put back' says the letters should be written in reverse.
'on' says to put letters next to each other.
'shelf' becomes 'ledge' (synonyms).
'wonk' in reverse letter order is 'know'.
'know'+'ledge'='KNOWLEDGE'
'from' is the link.
(Other definitions for knowledge that I've seen before include "Information, learning or enlightenment" , "Cognition, wisdom" , "practical skill" , "Information gained through experience" , "Awareness - erudition" .)