my @toRemove;
foreach my $item ( (@array1, @array2) ) {
   if ( $item =~ /$pattern/i ) {
      push(@toRemove, $item);
   }
}

foreach my $item ( @toRemove ) {
   @array1 = grep { $_ ne $item } @array1;
}

##</code><code>##

my @toRemove = grep m/$pattern/i, @array1, @array2;
my %toRemove = map { ($_ => 1) } @toRemove;
@array1 = grep ! $toRemove{$_}, @array1;

##</code><code>##

@array1 = grep ! m/$pattern/i, @array1;

##</code><code>##

splice @array,7,1;