The previous suggestion to use a module is fine, provided you read and understand the module documentation, so that you know what it's doing for you.

But for a case like this, a simple, direct use of the information in perlre, and the description of "qr" in perlop, would do just as well. You want to make sure that you don't get "false-alarm" matches, like having a match on a target word like "part" when the text file contains "compartment". So you want to enclose your list of words to match in parens, surrounded by word-boundaries, like this:

my @target_words = qw/list of words/;  # or read from a file, or whate
+ver
my $joined_targets = join "|", @target_words;
my $match_regex = qr/\b($joined_targets)\b/;

for my $file ( @file_list ) {
    open( F, "<", $file );
    while (<F>) {
        if ( /$match_regex/ ) {
            my $mathed_word = $1;
            store_to_db( $file, $matched_word );
            last;
        }
    }
    close F;
}
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Of course, if a target word like "work" is supposed to match on tokens like "works" and/or "worked", you should just make sure your list includes all the appropriate forms for each word.