Source : Webster's Revised Unabridged Dictionary (1913)

Approximate \Ap*prox"i*mate\, a. [L. approximatus, p. p. of
   approximare to approach; ad + proximare to come near. See
   {Proximate}.]
   1. Approaching; proximate; nearly resembling.

   2. Near correctness; nearly exact; not perfectly accurate;
      as, approximate results or values.

   {Approximate quantities} (Math.), those which are nearly, but
      not, equal.

Approximate \Ap*prox"i*mate\, v. t. [imp. & p. p.
   {Approximated}; p. pr. & vb. n. {Approximating}.]
   1. To carry or advance near; to cause to approach.

            To approximate the inequality of riches to the level
            of nature.                            --Burke.

   2. To come near to; to approach.

            The telescope approximates perfection. --J. Morse.

Approximate \Ap*prox"i*mate\, v. i.
   To draw; to approach.

Source : WordNet®

approximate
     adj 1: not quite exact or correct; "the approximate time was 10
            o'clock"; "a rough guess"; "a ballpark estimate" [syn:
             {approximative}, {rough}]
     2: very close in resemblance; "sketched in an approximate
        likeness"; "a near likeness" [syn: {near}]
     3: located close together; "with heads close together";
        "approximate leaves grow together but are not united"
        [syn: {close together(p)}]

approximate
     v 1: be close or similar; "Her results approximate my own" [syn:
          {come close}]
     2: judge tentatively or form an estimate of (quantities or
        time); "I estimate this chicken to weigh three pounds"
        [syn: {estimate}, {gauge}, {guess}, {judge}]