spellingout

Spellingout is the act of expressing something in its full form rather than in abbreviated or symbolic form. The term is used in two related domains: linguistic theory and practical writing.

In linguistics, spell-out refers to the process by which a syntactic structure is mapped onto a phonological representation. It marks the point at which linguistic features are converted into audible or visible form, typically at a phase boundary in theories of grammar. The concept helps explain how abstract syntactic objects become pronounced or written as words, letters, or sounds. Spell-out is concerned with the interface between syntax and phonology and is studied in relation to morphology, intonation, and punctuation. The term derives from the general meaning of “spell” as to name letters or sounds one by one.

In practical writing, to spell out something is to write or say it in full. Style guides commonly advise spelling out acronyms on first use (for example, National Aeronautics and Space Administration, NASA) and then using a short form thereafter. Numbers may be spelled out or written as digits depending on context and convention (for instance, “one hundred twenty-three” versus “123”). Spelling out also affects punctuation and hyphenation, such as spell-out numbers before nouns (“a forty-two-page report”) or the use of hyphenated forms for compound modifiers.

See also spelling, orthography, acronym. Etymologically, the term combines spell with out, reflecting the act of naming or rendering elements letter by letter or in full.