WILL definition

A person’s intent, volition, decision.
A legal document that states who is to receive a person’s estate and assets after their death.

Indicating intent to perform the action in the future, or expectation of an event in the future.

I will go to the store.

It will rain this afternoon.
Being ready to perform an action or comply with a request, see willing (verbal adjective).

He is willing to come tomorrow.
Indicating intent to perform the action in the future.
- William Shakespeare, Twelfth Night Or What You Will, act IV:
  
  Good fool, as ever thou wilt deserve well at my hand, help me to a candle, and pen, ink and paper : as I am a gentleman, I will live to be thankful to thee for’t.
- Alexandre Dumas, The Count of Monte Cristo, chapter LXXIII:
  
  “I will rejoin you, and we will fly ; but from this moment until then, let us not tempt Providence, Morrel; let us not see each other; it is a miracle, it is a providence that we have not been discovered; if we were surprised, if it were known that we met thus, we should have no further resource.”
Indicating expectation that the subject will perform the action in the future.

Historically, will was used in the simple future sense only in the second and third person, while shall was used in the first person. Today, that distinction is almost entirely lost, and the verb takes the same form in all persons and both numbers. Similarly, in the intent sense, will was historically used with the second and third person, while shall was reserved for the first person.
Historically, the present tense is will and the past tense is would.
See the usage note at shall.
Early Modern English had a past participle would which is now obsolete.

To try to make (something) happen by using one's will (intention).

All the fans were willing their team to win the game.
To bequeath (something) to someone in one's will (legal document).

He willed his stamp collection to the local museum.
To intend, decide to do something, wish strongly.

"Sophia can win the race if she wills it."