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definitions

and/or

[ and-awr ]
/ ˈændˈɔr /

conjunction

(used to imply that either or both of the things mentioned may be affected or involved): insurance covering fire and/or wind damage.

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Nearby words

and how!, and so forth, and the like, and then some, and thereby hangs a tale, and/or, andalusia, andalusite, andaman, andaman and nicobar islands, andaman islands
Can be confusedand and/or nor or1 (see usage note at and) (see usage note at the current entry)

Usage note

The combination and/or is used primarily in business and legal writing: All dwellings and/or other structures on the property are included in the contract. Because of these business and legal associations, some object to the use of this combination in general writing, where it occasionally occurs: She spends much of her leisure time entertaining and/or traveling. In such writing, either and or or is usually adequate. If a greater distinction is needed, another phrasing is available: Would you like cream or sugar, or both?
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for and/or

and/or

conjunction

(coordinating) used to join terms when either one or the other or both is indicatedpassports and/or other means of identification

usage

Many people think that and/or is only acceptable in legal and commercial contexts. In other contexts, it is better to use or both: some alcoholics lose their jobs or their driving licences or both (not their jobs and/or their driving licences)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Idioms and Phrases with and/or

and/or

Both or either of two options. For example, His use of copyrighted material shows that the writer is careless and/or dishonest. This idiom originated in legal terminology of the mid-1800s.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.