Noun

customary (plural customaries)

1. A book containing laws and usages, or customs; a custumal

Adjective

customary (comparative more customary, superlative most customary)

1. Agreeing with, or established by, custom; established by common usage; conventional; habitual.
2. Holding or held by custom; as, customary tenants; customary service or estate.

Quotations

• 1956 — Arthur C. Clarke, The City and the Stars, p 39

  When two people met for the first time in Diaspar—or even for the hundredth—it was customary to spend an hour or so in an exchange or courtesies before getting down to business, if any.

Related terms

• consuetude
• costumal
• costume
• custom
• customer
• customization
• customize

A convention is a set of agreed, stipulated or generally accepted standards, norms, social norms or criteria, often taking the form of a custom.

Certain types of rules or customs may become law and regulatory legislation may be introduced to formalise or enforce the convention (e.g., laws that define on which side of the road vehicles must be driven). In a social context, a convention may retain the character of an "unwritten" law of custom (e.g., the manner in which people greet each other, such as by shaking each other's hands).

In physical sciences, numerical values (such as constants, quantities, or scales of measurement) are called conventional if they do not represent a measured property of nature, but originate in a convention, for example an average of many measurements, agreed between the scientists working with these values.