1.VerbTo form (a word) from letters; say the letters in a word.
"He used Scrabble tiles to spell out “I LOVE YOU”."
2.VerbTo replace an acronym with its expansion.
"To avoid crypticness for nonexpert readers, she spelled out the phrase, so that "tips about PrEP in the context of OHS for HCPs" became "tips about preexposure prophylaxis in the context of occupational health and safety for health care professionals"."
3.VerbTo explain in clear and simple terms; to be explicit.
"Here is a brochure that spells out the benefits."