noun, na-adjective
beneficial and harmless; good with no drawbacks
Describes something that is entirely positive, with no negative side effects. Often used in formal or written contexts to emphasize safety and benefit.
このサプリメントは有益無害だと宣伝されている。
This supplement is advertised as beneficial and harmless.
彼の提案は有益無害なものだった。
His proposal was something beneficial and harmless.
A four-character compound (yojijukugo) combining 有益 (beneficial) and 無害 (harmless). The exact origin is uncertain, but it follows a common pattern of pairing positive and negative terms to express a complete idea.