Ad hoc is a Latin phrase meaning "for this". It generally signifies a solution designed for a specific problem or task, non-generalizable, and not intended to be able to be adapted to other purposes (compare a priori). Common examples are organizations, committees, and commissions created at the national or international level for a specific task. In other fields the term may refer, for example, to a military unit created under special circumstances, a tailor-made suit, a handcrafted network protocol, or a purpose-specific equation. Ad hoc can also mean makeshift solutions, shifting contexts to create new meanings, inadequate planning, or improvised events.
Read more about Ad Hoc: Ad Hoc Hypothesis, Ad Hoc Querying, Ad Hoc Military, Ad Hoc Networking