untin

un- +‎ tin

untin (third-person singular simple present untins, present participle untinning, simple past and past participle untinned)

1. (transitive) To remove the tin (metal) from.
   • 1884, Capt. W. Trague, “Treatment of Tin Ores from the Shaft's Mouth to the Smelting-House”, in Proceedings of the Mining Institute of Cornwall, volume 1, page 159:

     As regards the treatment of slimes, I think nothing so effective as the frame for untinning the stuff which is reduced to a pulp; hence the difficulty in dealing with it, and the great loss sustained by miners, whose lost tin is reproduced by the tin streamers or squatters who line the sides of the Red and other rivers.

untin

1. third-person plural present subjunctive form of untar
2. third-person plural imperative form of untar