Cómplice translates to "accomplice" or "confidant." While it can sometimes have a negative connotation in English, in Spanish, especially in a romantic context, it beautifully conveys a deep sense of shared understanding and partnership.
In this song, Kany Garcia uses it to describe her lover as "Un cómplice para el camino" (An accomplice for the journey). It highlights the idea of a partner who is not just a lover, but also a trusted friend and fellow traveler through life, making the relationship feel profound and adventurous.
Kany García spends this song refusing to say "I love you" directly. Instead she hands you a list. "Una lluvia fresca de mayo" (a fresh May rain). "Un buen poema de Darío" (a good poem by Darío, the Nicaraguan poet). "Un mate en un día de frío, eres tú" (a mate on a cold day, that's you). Every item is small and domestic, and they keep landing on the same two words, "eres tú" (that's you). Even the romance is unglamorous: the kiss she picks is "Un beso robado en la esquina" (a stolen kiss on the corner), and her word for a partner is "Un cómplice para el camino" (an accomplice for the road).
The chorus says what the list adds up to. "Saber que la vida se vuelve más vida si estás a mi lado" (knowing that life becomes more life if you're by my side) is the line people quote, and it is the grandest statement in the song. The better one comes right after, and it is deliberately unimpressive: there is "no hay mayor placer" (no greater pleasure) than "dormir abrazados" (sleeping in each other's arms). Not a wedding. Sleeping. By the final verse she has put the list down and simply asks, "corazón quédate a mi vera" (my love, stay by my side), using a word for "side" old enough that it sounds like something a grandparent would say.