"May all beings everywhere be happy and free and may the thoughts, words and actions of my own life contribute in some way to that happiness and to that freedom for all."
lokah: location, realm, all universes existing now,
samastah: all beings sharing that same location
sukhino (sukha): centered in happiness and joy, free from suffering
bhav: the divine mood or state of unified existence
antu: may it be so, it must be so (antu used as an ending here transforms this mantra into a powerful pledge, like in “I promise to do that”).