A metaphor is a figure of speech that compares two unlike things without using the words "like" or "as".
Here are some examples:
* "The city was a jungle." (The city is being compared to a jungle, suggesting its wild and dangerous nature.)
* "Time is money." (Time is being compared to money, emphasizing its value and limited nature.)
* "My heart is a lion." (The heart is being compared to a lion, suggesting strength and courage.)
Do you have a specific example in mind? Maybe you can tell me something you'd like to describe using a metaphor, and I can help you find a good comparison.