approximate

verb

  1. To estimate.

  2. To come near to; to approach.

  3. To carry or advance near; to cause to approach.

adjective

  1. Approaching; proximate; nearly resembling.

  2. Nearing correctness; nearly exact; not perfectly accurate.

    "NASA's Genesis spacecraft has on board an ion monitor to record the speed, density, temperature and approximate composition of the solar wind ions."

Synonyms: close
Antonyms: exact, precise