Collins COBUILD Advanced Learner’s Dictionary

1 ADJ [ADJ n] An acoustic guitar or other instrument is one whose sound is produced without any electrical equipment. ●  acous|ti|cal|ly /əkuː st I kli/ ADV □  …acoustically based music.

2 N‑COUNT If you refer to the acoustics or the acoustic of a space, you are referring to the structural features which determine how well you can hear music or speech in it. ●  acous|ti|cal|ly ADV [ADV adj] □  The church is acoustically perfect.

3 N‑UNCOUNT Acoustics is the scientific study of sound.

4 ADJ [ADJ n] Acoustic means relating to sound or hearing. Compare aural . □  …acoustic signals.

ac|quaint /əkwe I nt/ (acquaints , acquainting , acquainted )

1 VERB If you acquaint someone with something, you tell them about it so that they know it. If you acquaint yourself with something, you learn about it. [FORMAL ] □ [V n + with ] …efforts to acquaint the public with their rights under the new law. □ [V pron-refl + with ] I want to acquaint myself with your strengths and weaknesses.

2 → see also acquainted

ac|quaint|ance /əkwe I ntəns/ (acquaintances )

1 N‑COUNT [oft with poss] An acquaintance is someone who you have met and know slightly, but not well. □ [+ of ] The proprietor was an old acquaintance of his.

2 N‑VAR [oft poss N , on N ] If you have an acquaintance with someone, you have met them and you know them. □ [+ with ] He had met her through his acquaintance with Anne.

3 N‑UNCOUNT Your acquaintance with a subject is your knowledge or experience of it. [FORMAL ] □ [+ with ] They had little or no acquaintance with philosophy or history.

4 PHRASE When you make someone's acquaintance , you meet them for the first time and get to know them a little. [FORMAL ] □  I first made his acquaintance in the early 1960s.

ac|quaint|ed /əkwe I nt I d/

1 ADJ [v-link ADJ with n] If you are acquainted with something, you know about it because you have learned it or experienced it. [FORMAL ] □ [+ with ] He was well acquainted with the literature of France, Germany and Holland.

2 ADJ [v-link ADJ ] If you are acquainted with someone, you have met them and you know them. You can also say that two people are acquainted . [FORMAL ] □ [+ with ] No-one personally acquainted with the couple was permitted to talk to the Press. □  It's true we were acquainted, but no more than that.

3 ADJ [v-link ADJ ] If you get or become acquainted with someone that you do not know, you talk to each other or do something together so that you get to know each other. You can also say that two people get or become acquainted . □ [+ with ] The meetings were a way to get acquainted with each other.

4 → see also acquaint

ac|qui|esce /æ kwie s/ (acquiesces , acquiescing , acquiesced ) VERB If you acquiesce in something, you agree to do what someone wants or to accept what they do. [FORMAL ] □ [V + in/to ] Steve seemed to acquiesce in the decision. □ [V ] When her mother suggested that she stay, Alice willingly acquiesced.

ac|qui|es|cence /æ kwie s ^ə ns/ N‑UNCOUNT Acquiescence is agreement to do what someone wants, or acceptance of what they do even though you do not agree with it. [FORMAL ] □  Deirdre smiled her acquiescence.

ac|qui|es|cent /æ kwie s ^ə nt/ ADJ Someone who is acquiescent is ready to agree to do what someone wants, or to accept what they do. [FORMAL ] □  Perhaps you are too acquiescent.

ac|quire ◆◇◇ /əkwa I ə ^r / (acquires , acquiring , acquired )