Unsigned or unnamed; without a name or registration/signature (e.g., anonymous voting or an unsigned letter).
今回の選挙は無記名投票で行われた。
This election was conducted by secret (anonymous) ballot.
無記名の手紙が届き、内容に驚いた。
An unsigned letter arrived, and I was surprised by its contents.
寄付の多くは無記名で行われた。
Many of the donations were made anonymously.