optional

American  

[op-shuh-nl] / ˈɒp ʃə nl /

adjective

1. left to one's choice; not required or mandatory.

   Formal dress is optional.

   Synonyms:

   voluntary, elective, discretional

2. leaving something to choice.

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optional British  

/ ˈɒpʃənəl /

adjective

1. possible but not compulsory; left to personal choice

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Other Word Forms

• nonoptional adjective
• nonoptionally adverb
• optionality noun
• optionally adverb
• unoptional adjective
• unoptionally adverb

Etymology

Origin of optional

First recorded in 1755–65; option + -al ¹

Example Sentences

La Mirada Heights is marketed as an independent senior living community designed for older adults who can live on their own while receiving optional support services, according to the facility’s website.

From Los Angeles Times • Mar. 23, 2026

It also introduced an optional subscription package called Autonomy+ for driver-assistance features, such as hands-off driving.

From MarketWatch • Mar. 12, 2026

Under this system, students can attend optional learning modules before the official start of regular classes in the morning, during midday breaks, or later in the afternoon.

From Science Daily • Mar. 11, 2026

In the 32 years since its debut in Lillehammer, only four have been selected - even though there is an optional 18th place in the squad reserved for a woman.

From BBC • Mar. 10, 2026

Not only does it store information about the Phoenix Riders, but it also seems preset to serve the other teams, which means it has optional connections to everyone else’s NeuroLink accounts.

From "Warcross" by Marie Lu