1.Definition: being of the nature of a notion or concept
"To improve notional comprehension", "A notional response to the question"
2.Definition: indulging in or influenced by fancy
"All the notional vagaries of childhood"
3.Definition: not based on fact or investigation
"A notional figure of cost helps in determining production costs"
4.Definition: not based on fact; existing only in the imagination
"To create a notional world for oneself"