To say you "unvented" something is to say you figured it out, but are too humble to claim you "invented" or "discovered" it. "Unvent" is an acknowledgement that perhaps some other person, in similar circumstances, came up with the same solution before you did.
The term unvent was introduced to the knitting world by Elizabeth Zimmerman, knitter extraordinaire. EZ rarely claimed right of invention, instead giving credit to all that lies in the subconscious, influencing what the more egotistical of us regard as original creation.
The real significance of "unvent" is the acknowledgement that in any field, we stand on the shoulders of giants.