The Collaborative International Dictionary of English v.0.48:

Stoicism \Sto"i*cism\, n. [Cf. F. sto["i]cisme.]
   1. The opinions and maxims of the Stoics.
      [1913 Webster]

   2. A real or pretended indifference to pleasure or pain;
      insensibility; impassiveness.
      [1913 Webster]

WordNet (r) 3.0 (2006):

stoicism
    n 1: an indifference to pleasure or pain [syn: stoicism,
         stolidity, stolidness]
    2: (philosophy) the philosophical system of the Stoics following
       the teachings of the ancient Greek philosopher Zeno