As an adjective, ordinary.
As a noun relating to land, a plain is an area of land not significantly higher than adjacent areas and with relatively minor differences in elevation, such as a flood plain along a river or the Great Plains of the Mid-western United States.
"Plain People" refers to Amish, Mennonites, Quakers and other groups of Christians who hold to a simple life-style and do not artificially beautify their clothes or possessions.
It is Hebrew meaning "a fertile plain"
One homograph for "plain" is a noun meaning a large area of flat land. Another homograph is an adjective meaning simple or not fancy.
plain
E
Milan may be Gaulish in origin meaning "middle plain".
Plain well-meaning Briton. has written: 'A whipper for levelling Tommy' -- subject(s): Politics and government, Constitutional law
plain
The word is "steppe."
"In plain sight" is referring to something being in front of you without any type of obstructions blocking sight of it.
inconspicuous means that
ομαλός
easy, effortless, light, plain