3 ADJ [ADJ after v] If you do something unchallenged , nobody stops you and asks you questions, for example about who you are or why you are doing it. □ I managed to walk around unchallenged for 10 minutes before an alert nurse spotted me.
un|change|able /ʌ ntʃe I ndʒəb ə l/ ADJ Something that is unchangeable cannot be changed at all. □ The doctrine is unchangeable. □ …a thoroughly organised and almost unchangeable system of laws and customs.
un|changed /ʌ ntʃe I ndʒd/ ADJ [usu v-link ADJ ] If something is unchanged , it has stayed the same for a particular period of time. □ For many years prices have remained virtually unchanged.
un|chang|ing /ʌ ntʃe I ndʒ I ŋ/ ADJ Something that is unchanging always stays the same. □ …eternal and unchanging truths.
un|char|ac|ter|is|tic /ʌ nkær I ktər I st I k/ ADJ If you describe something as uncharacteristic of someone, you mean that it is not typical of them. □ [+ of ] It was uncharacteristic of her father to disappear like this. □ …an uncharacteristic lack of modesty. ● un|char|ac|ter|is|ti|cal|ly /ʌ nkær I ktər I st I kli/ ADV [usu ADV adj, oft ADV with v] □ Owen has been uncharacteristically silent. □ Uncharacteristically for him, he decided to have a snooze.
un|chari|table /ʌ ntʃæ r I təb ə l/ ADJ If you describe someone's remarks, thoughts, or behaviour as uncharitable , you think they are being unkind or unfair to someone. □ This was an uncharitable assessment of the reasons for the failure.
un|chart|ed /ʌ ntʃɑː r t I d/ ADJ [usu ADJ n] If you describe a situation, experience, or activity as uncharted territory or waters, you mean that it is new or unfamiliar. □ Carter's fourth album definitely moves into uncharted territory. □ …a largely uncharted area of medical science.
un|checked /ʌ ntʃe kt/ ADJ [ADJ after v, ADJ n, v-link ADJ ] If something harmful or undesirable is left unchecked , nobody controls it or prevents it from growing or developing. □ If left unchecked, weeds will flourish. □ …a world in which brutality and lawlessness are allowed to go unchecked.
un|civi|lized /ʌ ns I v I la I zd/ in BRIT, also use uncivilised ADJ If you describe someone's behaviour as uncivilized , you find it unacceptable, for example because it is very cruel or very rude. [DISAPPROVAL ] □ The campaign has abounded in mutual accusations of uncivilised behaviour. □ I think sport involving animals is barbaric and uncivilized.
un|claimed /ʌ nkle I md/ ADJ If something is unclaimed , nobody has claimed it or said that it belongs to them. □ Her luggage remained unclaimed at Frankfurt Departures. □ …unclaimed prizes.
un|clas|si|fied /ʌ nklæ s I fa I d/
1 ADJ If information or a document is unclassified , it is not secret and is available to the general public.
2 ADJ If something is unclassified , it has not been given a grade or put into a category, for example because it is of a low or basic standard. □ …an unclassified honours degree.
un|cle ◆◆◇ /ʌ ŋk ə l/ (uncles ) N‑COUNT ; N‑TITLE Someone's uncle is the brother of their mother or father, or the husband of their aunt. □ My uncle was the mayor of Memphis. □ A text from Uncle Fred arrived.
un|clean /ʌ nkliː n/
1 ADJ Something that is unclean is dirty and likely to cause disease. □ …the Western attitude to insects as being dirty and unclean. □ By bathing in unclean water, they expose themselves to contamination.
2 ADJ If you describe someone or something as unclean , you consider them to be spiritually or morally bad. □ They felt as though they had done something discreditable and unclean. □ …unclean thoughts.
un|clear /ʌ nkl I ə r /
1 ADJ [usu v-link ADJ ] If something is unclear , it is not known or not certain. □ It is unclear how much popular support they have among the island's population. □ Just what the soldier was doing in Bireij is unclear.
2 ADJ [v-link ADJ , ADJ as to wh/n, ADJ wh] If you are unclear about something, you do not understand it properly or are not sure about it. □ [+ about ] He is still unclear about his own future.
Uncle Sam /ʌ ŋk ə l sæ m/ N‑PROPER Some people refer to the United States of America or its government as Uncle Sam . [mainly AM , JOURNALISM ] □ They are ready to defend themselves against Uncle Sam's imperialist policies.
Uncle Tom (Uncle Toms ) N‑COUNT In the past, some black people used Uncle Tom to refer to a black man when they disapproved of him because he was too respectful or friendly towards white people. [OFFENSIVE , DISAPPROVAL ] □ They had earlier caused yet deeper offence when referring to him as an Uncle Tom.
un|clothed /ʌ nkloʊ ðd/ ADJ [ADJ n, v-link ADJ , ADJ after v] If someone is unclothed , they are not wearing any clothes. [FORMAL ] □ He learned how to draw the unclothed human frame. □ It's considered improper to be unclothed in public.
un|clut|tered /ʌ nklʌ tə r d/ ADJ If you describe something as uncluttered , you mean that it is simple and does not contain or consist of a lot of unnecessary things. □ If you keep a room uncluttered it makes it seem lighter and bigger. □ The portraits are simple, uncluttered compositions.
un|coil /ʌ nkɔ I l/ (uncoils , uncoiling , uncoiled ) VERB If something uncoils or if you uncoil it, it becomes straight after it has been wound or curled up. If someone who is curled up uncoils , they move so that their body becomes straight. □ [V n] He uncoiled the hose and gave them a thorough drenching. □ [V ] Dan played with the tangerine peel, letting it uncoil and then coil again. □ [V ] Mack seemed to uncoil slowly up into a standing position.