plain and lucid; articulate
Describes speech or writing that is clear, easy to understand, and well-expressed. Often used in formal or literary contexts.
His explanation was plain and lucid, and anyone could understand it.
I try to write in a plain and articulate style.
明快 also means clear and lucid, but is more common and less formal than 平明達意.
簡明 emphasizes simplicity and conciseness, while 平明達意 stresses both plainness and effective communication.
A four-character compound (yojijukugo) combining 平明 (plain, clear) and 達意 (conveying meaning). The exact historical origin is uncertain, but it follows a common pattern of pairing synonymous or complementary two-character words.