OPTIONAL

Pronunciation (US):

(GB):

IPA (US):

 Dictionary entry overview: What does optional mean? 

• OPTIONAL (adjective)
  The adjective OPTIONAL has 1 sense:

1. possible but not necessary; left to personal choice

  Familiarity information: OPTIONAL used as an adjective is very rare.

 Dictionary entry details 

• OPTIONAL (adjective)

Sense 1

Meaning:

Possible but not necessary; left to personal choice

Similar:

elective; facultative (not compulsory)

ex gratia (as a favor; not compelled by legal right)

nonmandatory; nonobligatory (not required by rule or law)

Antonym:

obligatory (morally or legally constraining or binding)

 Context examples 

An optional additional description of the observation result provided in a free text format.

(Observation Result Comment, NCI Thesaurus)

In the NCI Thesaurus an atom consists of a term string, a term type, a term source, and an optional term code.

(NCI Concept Atom, NCI Thesaurus)

Optional additional information about a laboratory procedure that can be planned, scheduled or performed in the framework of a particular study.

(Laboratory Procedure Comment, NCI Thesaurus)

A word or group of words indicating the identity of a person usually consisting of a first (personal) name and a last (family) name with an optional middle name.

(Person Name, NCI Thesaurus)

Every LSID consists of up to five parts: the Network Identifier (NID); the root DNS name of the issuing authority; the namespace chosen by the issuing authority; the object id unique in that namespace; and an optional revision id for storing versioning information.

(Life Sciences Identifier, NCI Thesaurus)

Due to alternative splicing, differential posttranslational modifications, optional binding to GHBP or alpha2-macroglobulin, and potential proteolytic processing, circulating GH shows great heterogeneity as a disulfide-linked or non-covalently associated monomer, dimer, trimer, tetramer, or pentamer in homopolymeric and heteropolymeric combinations.

(hGH Gene, NCI Thesaurus)