Simile (noun)

1. A figure of speech in which two fundamentally dissimilar things are explicitly compared, often in a phrase introduced by "like" or "as".
2. A comparison of one thing to another using "like" or "as" to make the comparison explicit.

Origin:

From latin similis ("like"). the word was first used in english in the late 16th century.

Examples:

1. She's as sweet as candy.
2. He was as quiet as a mouse.
3. The storm was like a hurricane.
4. The soldier was as brave as a lion.
5. Her voice was like a melody.