The term emergent curriculum is used in the context of child development to describe a technique for creating curriculum that is spontaneous and responsive to the child's needs in the moment.
When I speak to parents about our philosophical commitment to an emergent curriculum, I sometimes get a raised eyebrow that indicates the person I am taking to suspects that "emergent" really means "unplanned". Any veteran educator knows that using an emergent approach is like trying to give an important speach by going up in front of an unruly audience with the main points you want to make and a commitment to intuiting the crowds needs and responding to their questions in a way that gets your point across in a language they understand. Not for the faint of heart.
Emergence is a characteristic of complex, self organizing systems like culture, society, and the neural networks of the human brain. In a group of people, it means a level of complexity and coherence that emerges from a group that is not present in the individuals that make up the group. In the classroom that means gathering information using patience, flexibility, and observation in order to scaffold a conversation that speaks to the experience and needs of the group.