The Collaborative International Dictionary of English v.0.48:

Inquire \In*quire"\, v. i. [imp. & p. p. Inquired; p. pr. &
   vb. n. Inquiring.] [OE. enqueren, inqueren, OF. enquerre,
   F. enqu['e]rir, L. inquirere, inquisitum; pref. in- in +
   quarere to seek. See Quest a seeking, and cf. Inquiry.]
   [Written also enquire.]
   1. To ask a question; to seek for truth or information by
      putting queries.
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            We will call the damsel, and inquire. --Gen. xxiv.
                                                  57.
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            Then David inquired of the Lord yet again. And the
            Lord answered him.                    --1 Sam.
                                                  xxiii. 4.
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   2. To seek to learn anything by recourse to the proper means
      of knowledge; to make examination.
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            And inquire
            Gladly into the ways of God with man. --Miltom.
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   Note: This word is followed by of before the person asked;
         as, to inquire of a neighbor. It is followed by
         concerning, after, or about, before the subject of
         inquiry; as, his friends inquired about or concerning
         his welfare. "Thou dost not inquire wisely concerning
         this." --Eccl. vii. 10. It is followed by into when
         search is made for particular knowledge or information;
         as, to inquire into the cause of a sudden death. It is
         followed by for or after when a place or person is
         sought, or something is missing. "Inquire in the house
         of Judas for one called Saul of Tarsus." --Acts ix. 11.
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The Collaborative International Dictionary of English v.0.48:

Inquire \In*quire"\, v. t.
   1. To ask about; to seek to know by asking; to make
      examination or inquiry respecting.
      [1913 Webster]

            Having thus at length inquired the truth concerning
            law and dispense.                     --Milton.
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            And all obey and few inquire his will. --Byron.
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   2. To call or name. [Obs.] --Spenser.

   Syn: To ask; question. See Question.
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WordNet (r) 3.0 (2006):

inquire
    v 1: inquire about; "I asked about their special today"; "He had
         to ask directions several times" [syn: ask, inquire,
         enquire]
    2: have a wish or desire to know something; "He wondered who had
       built this beautiful church" [syn: wonder, inquire,
       enquire]
    3: conduct an inquiry or investigation of; "The district
       attorney's office investigated reports of possible
       irregularities"; "inquire into the disappearance of the rich
       old lady" [syn: investigate, inquire, enquire]

Moby Thesaurus II by Grady Ward, 1.0:

45 Moby Thesaurus words for "inquire":
   ask, ask a question, ask about, ask questions, be curious,
   bring into question, burn with curiosity, catechize, demand,
   dig around for, dig up, enquire, examine, explore, gape, gawk,
   inquire into, inquire of, inspect, interpellate, interrogate,
   investigate, look into, make inquiry, nose around for, nose out,
   peer, probe, propose a question, propound a question, put queries,
   query, question, quiz, require an answer, research, rubber,
   rubberneck, scrutinize, search, seek, stare, study, survey,
   want to know