Custom is a word with multiple meanings depending on the context:
1. As a noun: A traditional and widely accepted way of behaving or doing something that is specific to a particular society, place, or time.
2. As an adjective: Made or done to order for a particular customer.
3. In business: Refers to the government department that collects taxes on imports and exports.
4. In computing: Refers to modifications made to software or hardware to suit individual needs.