puer

noun2

1. •
   (historical) Dung (of dogs, fowls, etc) used in tanning, after applying lime, to soften skins.

   • A solution called the ‘pure’ or the 'pewer' (having never seen the word written.., we must spell it as pronounced) is prepared in a large vessel, and into this the skins are immersed. — 1842
2. •
   Ellipsis of puer aeternus.

   • You see, puers and puellas are always about to make a change; one day they’ll do what’s necessary—but not just yet. — 2005