Think about old tree (5)
I believe the answer is:
opine
'think' is the definition.
(I know that opine is a more specific form of anticipate)
'old tree' is the wordplay.
'old' becomes 'o' (abbreviation).
'tree' becomes 'pine' (pine is a kind of tree).
'o'+'pine'='OPINE'
'about' is the link.
(Other definitions for opine that I've seen before include "Conjecture" , "Give one's view" , "Think - express a view" , "Give opinion" , "Consider" .)