- left to one's choice; not required or mandatory: Formal dress is optional.
- leaving something to choice.
Origin of optional
SynonymsSee more synonyms for optional on Thesaurus.com
1. discretional, elective, voluntary.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for optionally
Optionally, it can live up to its description by crashing into targets and detonating a five-pound warhead.Smoke Rings, Mystery Backpacks and Gun-Toting Robots: The Weird Wartech of the Korean Conflict
April 3, 2014
At this time the sounds Hin and others may be made, alternately or optionally, according to habit.The Kama Sutra of Vatsyayana
By the Egyptians it was practised in the same manner (excepting their Priests) as by the Tyrians,—viz., optionally.
- possible but not compulsory; left to personal choice
Word Origin and History for optionally
Online Etymology Dictionary, © 2010 Douglas Harper