If you're never going to add to the dictionary, then the simplest thing to do is to load the dictionary as a constant property.
classdef t9
properties (Constant)
dict = i_loadDict()
end
...
end
function out = i_loadDict()
load('usdict.mat');
out = usdict;
end
There are ways to have something updateable, but this is the simplest solution to your problem.