Informal. A man; a male person. The guy at the coffee shop was really friendly.
A rope, cable, or cord used to steady, guide, or secure something. Each pole was held upright by a guy secured to the ground.
A figure representing Guy Fawkes, traditionally burned on a bonfire on Guy Fawkes Night. The children made a guy to burn on the bonfire for the celebration.
Informal, chiefly plural. People in general; a group of individuals of any gender, especially when addressed directly. "Hi guys, can I take your order?" the waiter asked.