The Collaborative International Dictionary of English v.0.48:

Unseconded \Un*sec"ond*ed\, a.
   1. Not seconded; not supported, aided, or assisted; as, the
      motion was unseconded; the attempt was unseconded.
      [1913 Webster]

   2. Not exemplified a second time. [Obs.] "Strange and
      unseconded shapes of worms." --Sir T. Browne.
      [1913 Webster]