IPA: /ˈpleɪn.nəs/
KK: /plɛnəs/
The state or quality of being simple, clear, or without decoration.
The plainness of her dress made it suitable for the formal event.
Plainness → It is formed from "plain" (from Old French *plain*, meaning flat or clear) and "-ness" (meaning the state or quality of). The word "plainness" refers to the quality of being clear or flat, without embellishment or complexity.
Think of something that is 'clear' or 'flat' ('plain') and the '-ness' indicating a state or quality. This helps you remember that 'plainness' means the quality of being simple or unadorned.