lacking a key or keys.
requiring no key or keys: a keyless lock operated by a series of push buttons.

Origin of keyless

First recorded in 1815–25; key1 + -less Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for keyless

Historical Examples of keyless

  • "Line clear" appears on the opening, and also at that of A's keyless disc.

    How it Works

    Archibald Williams

  • Unless his keyless indicator is at normal, he may not ask, "Is line clear?"

    How it Works

    Archibald Williams

  • A story which in the beginning is very like "The Keyless Chest."

  • There were two doors, the one I had entered by and another which was locked and keyless.

    Ghosts I Have Seen

    Violet Tweedale

  • Suppose there was a time when the piano was keyless, as a baby is toothless.