Source : Webster's Revised Unabridged Dictionary (1913)

Are \Are\ [AS. (Northumbrian) aron, akin to the 1st pers. pl.
   forms, Icel. erum, Goth. sijum, L. sumus, Gr. ?, Skr. smas;
   all from a root as. ? See {Am} and {Is}, and cf. {Be}.]
   The present indicative plural of the substantive verb to be;
   but etymologically a different word from be, or was. Am, art,
   are, and is, all come from the root as.

Are \Are\, n. [F., fr. L. area. See {Area}.] (Metric system)
   The unit of superficial measure, being a square of which each
   side is ten meters in length; 100 square meters, or about
   119.6 square yards.

Source : WordNet®

are
     n : a unit of surface area equal to 100 square meters [syn: {ar}]

be
     v 1: have the quality of being; (copula, used with an adjective
          or a predicate noun); "John is rich"; "This is not a
          good answer"
     2: be identical to; be someone or something; "The president of
        the company is John Smith"; "This is my house"
     3: occupy a certain position or area; be somewhere; "Where is
        my umbrella?" "The toolshed is in the back"; "What is
        behind this behavior?"
     4: have an existence, be extant; "Is there a God?" [syn: {exist}]
     5: happen, occur, take place; "I lost my wallet; this was
        during the visit to my parents' house"; "There were two
        hundred people at his funeral"; "There was a lot of noise
        in the kitchen"
     6: be identical or equivalent to; "One dollar equals 1,000
        rubles these days!" [syn: {equal}] [ant: {differ}]
     7: form or compose; "This money is my only income"; "The stone
        wall was the backdrop for the performance"; "These
        constitute my entire belonging"; "The children made up the
        chorus"; "This sum represents my entire income for a
        year"; "These few men comprise his entire army" [syn: {constitute},
         {represent}, {make up}, {comprise}]
     8: work in a specific place, with a specific subject, or in a
        specific function; "He is a herpetologist"; "She is our
        resident philosopher" [syn: {follow}]
     9: represent, as of a character on stage; "Derek Jacobi was
        Hamlet" [syn: {embody}, {personify}]
     10: spend or use time; "I may be an hour"
     11: have life, be alive; "Our great leader is no more"; "My
         grandfather lived until the end of war" [syn: {live}]
     12: to remain unmolested, undisturbed, or uninterrupted -- used
         only in infinitive form; "let her be"
     13: be priced at; "These shoes cost $100" [syn: {cost}]
     [also: {were}, {was}, {is}, {been}, {are}, {am}]

are
     See {be}