Gennētos (γεννητός) is an adjective meaning "born" — specifically born of a woman, existing as a natural human being. Jesus uses the phrase "among those born of women" (en gennētois gynaikōn) to describe all human beings and to magnify John the Baptist's greatness while also pointing to the greater greatness of the kingdom.
"Among those born of women there has arisen no one greater than John the Baptist. Yet the one who is least in the kingdom of heaven is greater than he" (Matthew 11:11) — this saying draws a line between the old covenant order (every person born of woman) and the new creation order (those born from above, John 3:3). The greatest natural human achievement is surpassed by the humblest position in God's kingdom — because kingdom membership is defined not by natural birth but by spiritual rebirth.