1. clear or distinct to the eye or ear: a plain trail to the river; to stand in plain view.
2. clear to the mind; evident, manifest, or obvious: to make one's meaning plain.
3. conveying the meaning clearly and simply; easily understood: plain talk.
4. downright; sheer; utter; self-evident: plain folly; plain stupidity.
5. free from ambiguity or evasion; candid; outspoken: the plain truth of the matter.
6. without special pretensions, superiorit
"suspicions can be plain upon faces."
"emotions can be plain on faces."
"countries can be plain for alls."
"churches can be plain on exteriors."
"bitternesses can be plain in interviews."
This list can help you learn new vocabulary more quickly and be able explore other words more easily.