Meaning

noun an aircraft that has a fixed wing and is powered by propellers or jets

noun (mathematics) an unbounded two-dimensional shape

noun a level of existence or development

originEtymology tree Proto-Indo-European *pleth₂-? Proto-Indo-European *pel-? Proto-Indo-European *pleh₂-der. Proto-Indo-European *pleh₂-no-s Proto-Italic *plānos Latin plānus Latin plānumder. English plane From Latin plānum (“flat surface”), a noun use of the neuter of plānus (“plain”). The word was introduced in the 17th century to distinguish the geometrical senses from the other senses of plain.…

Etymology from Wiktionary, CC BY-SA 3.0