An acid neutraliser is a substance that can be used to reduce the acidity of a solution. The term ACID NEUTRALISER can be broken down into six parts, each of which is a type of acid neutraliser: ALKALI (6 letters), AMINO (5 letters), BORIC (5 letters), FOLIC (5 letters), OLEIC (5 letters) and ACETIC (6 letters). ALKALI is a base that can be used to neutralise acids, while amino, boric, folic and oleic are all types of organic acids. ACETIC acid is a type of carboxylic acid.