spell vs spell out

spell is a noun but spell out is not a noun.

Word	Noun	Adjective	Verb	Adverb
spell	Yes	No	Yes	No
spell out	No	No	Yes	No

As verbs, spell and spell out are synonyms defined as:

spell and spell out: orally recite the letters of or give the spelling of

As verbs, spell out is a hyponym of spell; that is, spell out is a word with a more specific, narrower meaning than spell:

spell: write or name the letters that comprise the conventionally accepted form of (a word or part of a word)
spell out: spell fully and without abbreviating

Other hyponyms of spell include hyphen, hyphenate.

spell (noun)	spell out (noun)
a verbal formula believed to have magical force
a psychological state induced by (or as if induced by) a magical incantation
a time period for working (after which you will be relieved by someone else)
a period of indeterminate length (usually short) marked by some action or condition

spell (verb)	spell out (verb)
take turns working	make explicit; specify in detail
orally recite the letters of or give the spelling of	orally recite the letters of or give the spelling of
indicate or signify	spell fully and without abbreviating
place under a spell
write or name the letters that comprise the conventionally accepted form of (a word or part of a word)
relieve (someone) from work by taking a turn