Assuming the file is small enough to slurp, then split does the job nicely:

#! perl -slw
use strict;

my @array = split 'term', do{ local $/; <DATA> };
shift @array; ## Discard leading null

print '---', "\n", $_, "\n" for @array;

__DATA__
term {
yada yada
12345
() ...
}

term only occurs here {
could be 30 lines here
but never that word again until
another block starts
yadada
}

term, etc.
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That discards the term itself. If you want to retain the term in each element, then perhaps the simplest way is to just put it back after the split. Just substitute this line into the above.

my @array = map{ "term$_" } split 'term', do{ local $/; <DATA> };
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