optional

adjective

op·​tion·​al ˈäp-sh(ə-)nəl 

: involving an option : not compulsory

optionality

ˌäp-shə-ˈna-lə-tē 

noun

optionally adverb

Synonyms of optional

• voluntary
• elective
• discretionary

Examples of optional in a Sentence

Jackets are required at the restaurant, but ties are optional.

Many optional features are available on this car.

Registration is optional, not mandatory.

Recent Examples on the Web

Nonprofits don’t have to attend the Buildfest to enjoy the fruits of its labor, though an optional 30-minute focus group session in advance would help the students understand each agency’s mission and needs. —Frederick Melo, Twin Cities, 18 Feb. 2026

Throughout the year, Muslims pray five times a day, and in Ramadan, there is a sixth optional prayer, Ali said. —Sean Krofssik, Hartford Courant, 18 Feb. 2026

Plenty of onboard tech, including a customizable large touchscreen, separate driver display, and optional head-up display. —New Atlas, 18 Feb. 2026

Additionally, a sixth prayer, optional, called the Tarawih prayer, is recited in the evening, along with the five daily prayers practiced year-round. —Marina Johnson, IndyStar, 18 Feb. 2026

Word History

First Known Use

1765, in the meaning defined above

Kids Definition

optional

adjective

op·​tion·​al ˈäp-shnəl 

-shən-ᵊl

: left to one's choice : not required

optional equipment on a new car

optionally

-ē

adverb