An omnibus clause is a clause

Clause

In grammar, a clause is the smallest grammatical unit that can express a complete proposition. In some languages it may be a pair or group of words that consists of a subject and a predicate, although in other languages in certain clauses the subject may not appear explicitly as a noun phrase,...

 that provides or includes all residuary not specifically mentioned.

A very common omnibus clause deals with automobile liability insurance

Liability insurance

Liability insurance is a part of the general insurance system of risk financing to protect the purchaser from the risks of liabilities imposed by lawsuits and similar claims. It protects the insured in the event he or she is sued for claims that come within the coverage of the insurance policy...

. The clause provides coverage for the named insured, any member of the insured's household, and to any person using the automobile with the insured's permission, provided the use was within the scope of permission

Permission

Permission, in philosophy, is the attribute of a person whose performance of a specific action, otherwise ethically wrong or dubious, would thereby involve no ethical fault. The term "permission" is more commonly used to refer to consent...

.

A second common omnibus clause is used in wills. The clause distributes to the named beneficiary all unnamed assets included in the decedent's estate.