use strict;
use warnings;

# ... initialize some path and file names ...

# Open file with search items

my %terms;
open(FILE,"<$ssearch") or die "$ssearch: $!";
while (<FILE>) { # use $_
    chomp;
    my ( $term, $newterm ) = split /-/;
    $terms{$term} = $newterm;
}

# Open file with list of files to be searched

open(FILE,"<$fsearch") or die "$fsearch: $!";
my @sigfiles = <FILE>;
chomp @sigfiles;

# loop over the files to be searched

for my $file ( @sigfiles ) {
    open( IFILE, $file ) or die "$file: $!";
    open( OFILE, ">$dir/REVISE_$file" or die "$dir/REVISE_$file: $!";

# loop over lines in the file
    while (<FILE>) {

  ## at this point, it's hard to tell what you really want to do...
  ## you can refer to "keys %terms" and "values %terms" and "$terms{$key}" ...

    }

 ## do you need to print something to your output that serves as 
 ## some sort of "summary" for each input file? If so, do that here.
 ## (you probably should simplify/combine your various printf statements)

}