If you enable the Wiktionary option in Learning & Settings the bot will automatically lookup new words in Wiktionary and import their definition, meaning, and synonyms into its object database.
The "WhatIs" script can also lookup and import the data on object from WikiData (Wikipedia's database).
Knowing the definition of fly is not enough to know if birds fly. You would also need to know what a bird is, and have the knowledge that a bird can fly.
I think with the Understanding script you could tell a bot this.
you: birds can fly.
bot: I understand, birds can fly.
you: can birds fly?
bot: Yes, birds can fly.