Plain
/pleɪn/noun
Flat and level, or clear and simple in form or expression.
Did you know?English plain ultimately comes through Old French from Latin *planus*, and that same root also gave us words for something that is literally “level” or “smooth” in the old Roman world.
Etymological Timeline
Proto-Indo-European
PIE
*pleh₂-
“to spread flat, make broad”
Latin
Latin
planus
“flat, level, smooth”
Old French
Old French
plain
“flat, level; open country”
Middle English
English
plain
“flat land; clear, simple, not ornate”
Modern English
English
plain
“flat and level, or clear and simple in form or expression”