1. juxtaposition: the relative position of two things that are next to each other
2. grammar relationship between noun phrases: the relationship between two usually consecutive nouns or noun phrases that refer to the same person or thing and have the same relationship to other sentence elements. In the sentence "My son, an actor, lives with me," the phrase "My son, an actor" is an example of apposition.
3. physiology cell growth in layers: cell growth in which layers of material are deposited on existing ones
