messmess1noun (no plural)1a lot of untidy or dirty things all in the wrong place: Your bedroom is in a mess.Don't make a mess in the kitchen.2a person or thing that is untidy or dirty: My hair is a mess!3a difficult situation: She's in a mess – she's got no money and nowhere to live.messmessmessesmessedmessing2verb (messes, messing, messed)mess about, mess aroundto behave in a silly way: Stop messing around and finish your work!mess something up1to do something badly or make something go wrong: The bad weather messed up our plans for the weekend.2to make something untidy or dirty: Don't mess my hair up!