Longman Dictionary of Contemporary English - muck

~1 n informal 1 especially BrE something such as dirt, mud, or another sticky substance that makes something dirty  (Come on, let's wipe that muck off your face.) 2 BrE waste matter from animals, especially waste matter that is put on land to make plants grow better  (dog muck | They were shovelling muck onto the fields.) 3 something that is unpleasant or of very bad quality  (How can you eat that muck? It looks disgusting. | All that paper ever prints is muck about people's sex lives.) 4 as common as muck BrE old-fashioned an insulting way of describing someone of a low social class ~2 v muck about/around phr v BrE informal 1 to behave in a silly way, especially when you should be working or paying attention to something; mess around (mess2)  (Stop mucking about and listen! | We spent the days mucking around on the beach.) 2 T muck someone/something about/around) to cause trouble and inconvenience for someone, especially by changing your mind a lot; mess around (mess2)  (The travel agent has really been mucking me around over this holiday.) muck in phr v BrE informal 1 to work together with other people in order to get a job done; pitch in (pitch1)  (Oh, stop moaning - we've all got to muck in!) 2 to share things with other people  (We're a bit short of space. Do you mind mucking in with the other boys?) muck sth out phr v to clean the place where an animal lives  (to muck out the stables) muck sth up phr v BrE informal 1 to do something wrong or badly, so that you fail to achieve something  (I really mucked up those last two exams.) 2 to spoil something, especially an arrangement or plan  (The bad weather mucked up our plans for a picnic.) 3 to make something dirty  (Don't muck up your shirt.)