Surprise Jump

Say that you're just walking along minding your own business, or just standing around doing nothing. Everything is calm and peaceful, with no sign of danger or anything. Looks like today will be a nice, quiet-

-horn honks-

AAAAAAAAAAAAAAHHHHHHHHHHHHHHHHHH!!!!!!!!!!!!!!!!!!!!!!!!!!

You've suddenly jumped up from surprise all because a horn honked.

Essentially, this trope is Exactly What It Says on the Tin. A character becomes so surprised from something, or gets his foot stepped on, that he jumps like 10 or 20 feet in the air. Maybe even more than that, before coming back down again.

Compare Cat Scare, Wild Take, Catapult Nightmare. Contrast: Jump Scare.

Anime and Manga

 * A stock gag in Ranma ½ results in Ranma clinging to the ceiling if he is scared enough.
 * In Parasyte, a nervous Shinichi is tugged at from behind by a young girl.

Newspaper Comics

 * Several Garfield strips had this happen to Jon, usually when Garfield scares him.
 * A Peanuts strip had Charlie Brown and Sally walking to school. While waiting for the bus, Charlie Brown tells Lucy that Sally is so scared about her first day of kindergarten that if someone even mentions kindergarten while she's around, she'd jump 30 feet in the air. Putting this theory to the test, Lucy says "Kindergarten" to Sally, who then promptly jumps up into the air in fear. Lucy then muses, "Only 10 feet. I knew you were exaggerating."
 * Magazine example: Buzz Beamer in Sports Illustrated for Kids watched a demonstration of a device called the "what-the," which measures a player's jump height after being slammed on the floor right behind the player (hence the Curse Cut Short name).

Video Games
"GLaDOS: Did you know that people with guilty consciences are more easily startled by loud nois-[train horn]"
 * Referenced in Portal 2:

Western Animation

 * Winnie the Pooh: Rabbit fell victim to this trope when he asked Winnie to call for Christopher Robin. Pooh literally called Christopher Robin which was what scared Rabbit.
 * Garfield also did this a few times in Garfield and Friends when startled by either Nermal or Binky the Clown.
 * Scooby-Doo also did this lots of times in all cartoon incarnations.
 * There was a series of Looney Tunes shorts in which a puppy would run behind a cat and bark loudly, causing the cat to jump up in shock and hold on to the ceiling. When there wasn't a ceiling, the cat would end up on a tree, a telephone pole, or even the wing of a passing airplane.
 * Also happened a lot to Wile E. Coyote when the Roadrunner sneaks up from behind and goes "Meep-meep!" And to Sylvester when he's going after Speedy Gonzalez.
 * An episode of Clifford the Big Red Dog had Clifford and Cleo trying to help T-Bone get over his fear of loud noises. T-Bone even jumped up into the air a couple of times whenever he heard a loud noise.
 * Ray Stantz also fell victim to this trope in the The Real Ghostbusters episode, "Look Homeward, Ray".

Real Life

 * Some hoofed animals, such as fallow deer, reflexively jump straight up in the air when startled. It's thought to display how athletic they are, so that predators will think twice about chasing them.
 * Not just hooved animals. The main reason why armadillos often get hit by cars is that they jump when frightened. If they just curled up, the car would often pass over them harmlessly.