sign
US /saɪn/
UK /saɪn/

1.
2.
a gesture or action used to convey information or instructions
:
•
He gave a sign to the waiter to bring the bill.
•
She communicated with him using hand signs.
3.
an event or circumstance that indicates a future outcome; an omen
:
•
The dark clouds were a sign of the coming storm.
•
His sudden silence was a bad sign.
1.
write one's name on (something) to authorize it or show one's agreement, acceptance, or obligation
:
•
Please sign your name at the bottom of the form.
•
She agreed to sign the contract.