mess / mes/ • n. [usu. in sing.] 1. a dirty or untidy state of things or of a place: she made a mess of the kitchen my hair was a mess. ∎  a thing or collection of things causing such a state: she replaced the jug and mopped up the mess. ∎  a person who is dirty or untidy: I look a mess. ∎  a portion of semisolid or pulpy food, esp. one that looks unappetizing: a mess of mashed black beans and rice. ∎  used euphemistically to refer to the excrement of a domestic animal: dog mess. ∎ fig. a situation or state of affairs that is confused or full of difficulties: the economy is still in a terrible mess. ∎ fig. a person whose life or affairs are confused or troubled: he needs treatment of some kind—he's a real mess.2. a building or room in which members of the armed forces take their meals; mess hall: the sergeants' mess. ∎  a meal taken there.• v. 1. [tr.] make untidy or dirty: you've messed up my beautiful carpet. ∎  [intr.] (of a domestic animal) defecate: they had some problems with dogs messing in the store. ∎  make dirty by defecating: he feared he would mess the bed.2. [intr.] take one's meals in a particular place or with a particular person, esp. in an armed forces' mess: I messed at first with Harry, who was to become a lifelong friend they messed together.PHRASES: mess with someone's head inf. cause someone to feel frustrated, anxious, or upset.PHRASAL VERBS: mess around/about behave in a silly or playful way, esp. so as to cause irritation. ∎  spend time doing something in a pleasantly desultory way, with no definite purpose or serious intent: messing about in boats.mess around/about with interfere with: we don't want outsiders messing around with our schools. ∎ inf. engage in a sexual relationship with (someone, esp. the partner of another person).mess up inf. mishandle a situation: he singled out the health care fiasco as an example of how the government has messed up.mess someone up inf. cause someone emotional or psychological problems: I was unhappy and really messed up. ∎  inflict violence or injury on someone: the wreck messed him up so much that he can't walk.mess something up inf. cause something to be spoiled by inept handling: an error like that could easily mess up an entire day's work.mess with inf. meddle or interfere with so as to spoil or cause trouble: stop messing with things you don't understand.ORIGIN: Middle English: from Old French mes ‘portion of food,’ from late Latin missum ‘something put on the table,’ past participle of mittere ‘send, put.’ The original sense was ‘a serving of food,’ also ‘a serving of liquid or pulpy food,’ later ‘liquid food for an animal’; this gave rise (early 19th cent.) to the senses ‘unappetizing concoction’ and ‘predicament,’ on which sense 1 is based. In late Middle English the term also denoted any of the small groups into which the company at a banquet was divided (who were served from the same dishes); hence, ‘a group of people who regularly eat together’ (recorded in military use from the mid 16th cent.).