If I add strictures (use strict; use warnings;) to your sample code:

use strict;
use warnings;

my $name = "Father" ;
my @terms = qw(Mom Wife Son Daughter);
my %fam_old = map{ $tool => { $_,1 }} @terms;
print Dumper \%fam_old,"\n";
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it prints:

Global symbol "$tool" requires explicit package name at ...\noname.pl 
+line 6.
Execution of ...\noname.pl aborted due to compilation errors.
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Mybe you intended the hash assignment to be:

my %fam_old = map{$_, 1} @terms;
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in which case the code prints:

$VAR1 = {
          'Son' => 1,
          'Daughter' => 1,
          'Wife' => 1,
          'Mom' => 1
        };
$VAR2 = '
';
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