Collins COBUILD Advanced Learner’s Dictionary

2 ADJ If you describe something or someone as unacknowledged , you mean that their existence or importance is not recognized officially or publicly. □  This tradition goes totally unacknowledged in official guidebooks.

un|ac|quaint|ed /ʌ nəkwe I nt I d/ ADJ [v-link ADJ with n] If you are unacquainted with something, you do not know about it or do not have not any experience of it. □ [+ with ] I was then totally unacquainted with his poems.

un|adorned /ʌ nədɔː ^r nd/ ADJ Something that is unadorned is plain, rather than having decoration on it. □  The room is typically simple and unadorned, with white walls and a tiled floor.

un|adul|ter|at|ed /ʌ nədʌ ltəre I t I d/

1 ADJ Something that is unadulterated is completely pure and has had nothing added to it. □  Organic food is unadulterated food produced without artificial chemicals or pesticides.

2 ADJ [ADJ n] You can also use unadulterated to emphasize a particular quality, often a bad quality. [EMPHASIS ] □  Sheer unadulterated greed should never be part of any system.

un|af|fect|ed /ʌ nəfe kt I d/

1 ADJ [v-link ADJ ] If someone or something is unaffected by an event or occurrence, they are not changed by it in any way. □ [+ by ] She seemed totally unaffected by what she'd drunk. □  The strike shut down 50 airports, but most international flights were unaffected.

2 ADJ If you describe someone as unaffected , you mean that they are natural and genuine in their behaviour, and do not act as though they are more important than other people. [APPROVAL ] □  …this unaffected, charming couple.

un|afraid /ʌ nəfre I d/ ADJ [v-link ADJ , ADJ after v, ADJ to-inf] If you are unafraid to do something, you are confident and not at all nervous about doing it. □ [+ of ] He is a man with a reputation for being tough and unafraid of unpopular decisions. □  She was a forceful intellectual unafraid to speak her mind.

un|aid|ed /ʌ ne I d I d/ ADJ [usu ADJ after v, oft ADJ n] If you do something unaided , you do it without help from anyone or anything else. □  There had been at least thirteen previous attempts to reach the North Pole unaided.

un|al|loyed /ʌ nəlɔ I d/ ADJ [usu ADJ n] If you describe a feeling such as happiness or relief as unalloyed , you are emphasizing that it is a strong feeling and no other feeling is involved. [LITERARY , EMPHASIS ] □  …an occasion of unalloyed joy.

un|al|ter|able /ʌ nɔː ltərəb ^ə l/ ADJ [usu ADJ n] Something that is unalterable cannot be changed. □  …an unalterable fact of life.

un|al|tered /ʌ nɔː ltə ^r d/ ADJ [v-link ADJ , ADJ after v, ADJ n] Something that remains unaltered has not changed or been changed. □  The rest of the apartment had fortunately remained unaltered since that time. □  These were my opinions, and they continue unaltered.

un|am|bigu|ous /ʌ næmb I gjuəs/ ADJ If you describe a message or comment as unambiguous , you mean that it is clear and cannot be understood wrongly. □  …an election result that sent the party an unambiguous message. ●  un|am|bigu|ous|ly ADV [usu ADV with v, oft ADV adj] □  He has failed to dissociate himself clearly and unambiguously from the attack.

un|am|bi|tious /ʌ næmb I ʃəs/

1 ADJ An unambitious person is not particularly interested in improving their position in life or in being successful, rich, or powerful.

2 ADJ An unambitious idea or plan is not very complicated, risky, or new, and is easy to carry out successfully.