What does "rattlesnake" mean?

Any of various venomous American snakes, of genera Crotalus and Sistrurus, having a rattle at the end of its tail.

What is a synonym for "rattlesnake"?

Common synonyms include: dangerous, pit viper, rattle snake, rattler, rattlers, rattlesnake like.

Pronounced //ˈɹæt.əlˌsneɪk//.

/ˈɹæt.əlˌsneɪk/ noun

noun ·Uncommon ·Advanced level

Noun

1
Any of various venomous American snakes, of genera Crotalus and Sistrurus, having a rattle at the end of its tail.
"Hooded rattlesnakes, horned toads, and lizards crawl in the dust and among the rocks."
2
pit viper with horny segments at the end of the tail that rattle when shaken wordnet

"Tom was bitten by a rattlesnake."

From rattle + snake.