while (my $line = <INFILE>) {
    my @words;
    while ($line =~ /\S+/g) {
        push @words, lc $1;
    }
    for my $word (@words) {
        if (exists $dict{$word}) { $line =~  s/$word/$dict{$word}/gi }
    }
    print $line;
}

##</code><code>##

    my ( $key, $val ) = /^(\d+)\s+([\w-]+)/;
   ...
    my $pattern = quotemeta "\b([$cc]{$min,$max})\b/";