The Collaborative International Dictionary of English v.0.48:

Scram \Scram\ (skr[a^]m), n.
   the rapid shut down of a nuclear reactor, as in an emergency.
   [PJC]

The Collaborative International Dictionary of English v.0.48:

Scram \Scram\ (skr[a^]m), v. i. [imp. & p. p. Scrammed; p. pr.
   & vb. n. Scramming.]
   to leave; to go away; used mostly as an impolite command to a
   person to go away from a specific location. [informal]
   [PJC]

The Collaborative International Dictionary of English v.0.48:

Scram \Scram\ (skr[a^]m), v. t. [imp. & p. p. Scrammed; p. pr.
   & vb. n. Scramming.]
   to shut down (a nuclear reactor) quickly, as in an emergency.
   [PJC]

WordNet (r) 3.0 (2006):

scram
    v 1: leave immediately; used usually in the imperative form;
         "Scram!" [syn: scram, buzz off, fuck off, get,
         bugger off]

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "scram":
   be off, beat it, begone, blow, clear out, decamp, dog it,
   duck and run, duck out, flake off, get, get going, get lost,
   get out, git, hightail, hit the road, kite, lam,
   make yourself scarce, shove off, skedaddle, skin out, split,
   take a powder, take off, vamoose