Dope that is one encouraging wishful thinking? (5)
I believe the answer is:
genie
'one encouraging wishful thinking?' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'dope that is' is the wordplay.
'dope' becomes 'gen' (both can mean information).
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'gen'+'ie'='GENIE'
Can you help me to learn more?
(Other definitions for genie that I've seen before include "Obedient spirit of Arabian folklore" , "Goblin as found in Aladdin's lamp" , "In Arabian Nights, a magic goblin" , "He came from Aladdin's lamp" , "Magical being who carries out a person's wishes" .)