optional

option + -al

• (UK) IPA ^(key): /'ap.S@.n@l/
• (US) IPA ^(key): /'ap.S@.n@l/

• Audio (UK)

  (file)

1. If something is optional, you may choose it or not.
   • Synonym: elective
   • Antonym: compulsory

   At this event, dress is optional.