An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

The act or instance of removing the contribution of non-related, intervening foreground light to the object.

→ sky; → subtraction.

To take one number away from another; deduct. To perform the arithmetic operation of → subtraction.

From L. subtractus, p.p. of subtrahere "to draw from beneath, take away, draw off," from → sub- "from under" + trahere "to pull, draw."

Zirkaršidan, literally "to draw beneath," from zir-, → sub-, + karšidan "to draw, pul, drag," variant of kašidan "to draw, protract, trail, drag, carry;" Av. karš- "to draw; to plow," karša- "furrow;" Proto-Iranian *kerš-/*xrah- "to draw, plow;" cf. Skt. kars-, kársati "to pull, drag, plow;" Gk. pelo, pelomai "to move, to bustle;" PIE base k^wels- "to plow."
Kâhidan, → decrease.

The operation of finding the difference between two numbers or quantities.

Verbal noun of → subtract.

1) Constituting or involving → subtraction.
2) Math.: Indicating or requiring subtraction; having a → minus sign.

→ subtract; → -ive.

Color produced by mixing pigments rather than light. Mixing all of the subtractive colors together results in the color black. See also → additive color.

→ subtractive; → color.