noun

• (grammar) A construction in which one noun or noun phrase is placed with another as an explanatory equivalent, both of them having the same syntactic function in the sentence.
• (grammar) The relationship between such nouns or noun phrases.
• The quality of being side by side, apposed instead of opposed, next to each other.
• A placing of two things side by side, or the fitting together of two things.
• (biology) The growth of successive layers of a cell wall.
• (rhetoric) Appositio, the addition of an element not syntactically required.
• A public disputation by scholars.
• (UK) A (now purely ceremonial) speech day at St Paul's School, London.