noun

• (uncountable) The act, practice, ability, or subject of forming words with letters, or of reading the letters of words; orthography.
  "For the practical use of spelling comes in writing."
• (uncountable) The manner of spelling of words; correct spelling.
  "Because Elizabethan spelling was fluid, editors feel free to ‘modernize’ (correct) the spelling in the quartos and the Folio. But how is one to spell Rosencratz or Guildenstern, where the spelling varies, not only from text to text, but even within texts?"
• (countable) A specific spelling of a word.
  "[p 253] *excellent Q2’s ‘extent’ is generally dismissed as an error, probably a mis-reading of ‘exlent’, a common spelling at this time. [p 269] reverend The spellings ‘reuerent’ (Q2) and ‘Reuerend’ (F) were interchangeable at this time. [p 466] Guildensterne and Rosincrance are F’s consistent spellings."
• (US, rare, dated, countable or uncountable) A spelling test or spelling bee.
  "The boys were anxious for a spelling in the evening but I said no."