use strict;
use warnings;
use Data::Dumper;

my @AoA = (['a','b','c'],
           ['a','b','c'],
           ['a','b','d'],
           ['a','b','d']);

my (%h, @uAoA);
for (@AoA) { push @uAoA, $_ if !$h{join $;, @$_}++; }

print Dumper \@uAoA;