What does liberi in latin mean?

Answer 1

Liberi is either

• the nominative/vocative plural of the word for "children"
• the masculine or neuter genitive singular of the adjective meaning "free"
• the masculine nominative/vocative plural of the adjective meaning "free"

As such it means

• "children" (sentence subject) or "O children!"
• "of the free "
• "the free " (sentence subject) or "O free !"