An Etymological Dictionary of Astronomy and Astrophysics

1a) A scheme or method of acting, doing, proceeding, making, etc., developed in advance.

1b) A representation of a thing drawn on a plane, as a map or diagram.

2a) To arrange a method or scheme beforehand for.

2b) To make plans for (Dictionary.com).

Etymology (EN): M.E., from Fr. plan “ground plan, map,” literally “plane surface,” from L. planum “level or flat surface,” noun use of adjective planus “level, flat” (from PIE root *pele- “flat; to spread;”

Gk. plassein “to mold,” plasma “something molded or created;” L. planus “flat, level, even, plain, clear;” Lith. plonas “thin;” O.C.S. polje “flat land, field,” Russ. polyi “open;” O.E. feld, M.Du. veld “field.”

Etymology (PE): Pišgâr, literally “beforehand written, painted in advance,” from piš- “before, in front,” → pre-, + gâr present stem of negâridan, negâštan “to paint, write,” → graph.