The Collaborative International Dictionary of English v.0.48:

Penicil \Pen"i*cil\ (p[e^]n"[i^]*s[i^]l), n. [L. penicillum,
   penicillus, a painter's brush, a roil of lint, a tent for
   wounds.] (mented.)
   A tent or pledget for wounds or ulcers.
   [1913 Webster]