na-adjective, noun
open-hearted; free and easy; frank
Describes a personality that is broad-minded, unpretentious, and not bothered by small details. Often used in literary or formal contexts.
彼の磊落な人柄に、誰もが好感を持った。
Everyone liked his open-hearted personality.
磊落な態度で、細かいことは気にしない。
With a free and easy attitude, he doesn't worry about small things.
The exact derivation is uncertain. The kanji 磊 (many stones) and 落 (fall) together suggest a broad, unconfined quality, conventionally associated with an open-hearted personality.