the market for replacement parts, accessories, and equipment for the care or enhancement of the original product, especially an automobile, after its sale to the consumer: The company holds a large share in the automotive radio aftermarket.
any additional market created by a product after the primary market: Television is the perfect aftermarket for old movies.
Stock Exchange. secondary market.
Origin of aftermarket
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Online Etymology Dictionary, © 2010 Douglas Harper