Versos libres, or free verse, refers to a form of poetry that does not adhere to a specific meter or rhyme scheme. This style allows poets greater freedom in expression, as they can vary line lengths, rhythms, and patterns. In the context of Nancy Morejón's 'Mujer negra,' this technique is significant because it reflects the complexities of identity, culture, and the female experience, enhancing the emotional depth of her work.