Rat/ræt/ Definition 1 of 3Pro Tip 1/3Negative Connotations The word 'rat' can suggest dirtiness or disease, especially in urban settings. The abandoned warehouse was swarming with rats. Pro Tip 2/3Associated Behaviors 'Rat' is often used to describe animals that are sneaky or thieving. A rat stole food from the kitchen. Pro Tip 3/3Common Metaphor 'Rat race' is a metaphor for the competitive struggle of daily life. I'm tired of this rat race and want to retire.