plan (n.) Look up plan at
1670s as a technical term in perspective drawing; 1706 as "drawing, sketch, or diagram of any object," from French plan "ground plan, map," literally "plane surface" (mid-16c.), from Latin planum "level or flat surface," noun use of adjective planus "level, flat" (see plane (n.1)). The notion is of "a drawing on a flat surface." Meaning "scheme of action, design" is first recorded 1706, possibly influenced by French planter "to plant," from Italian planta "ground plan."
plan (v.) Look up plan at
1728, "make a plan of," from plan (n.). Related: Planned; planning; plans. Planned economy is attested from 1931. Planned Parenthood (1942) formerly was Birth Control Federation of America.