"Maize starch" refers to a type of starch that is derived from corn. It is a powdery substance commonly used in cooking and baking as a thickening agent. Full definition
I feel that there's a misconception that it's not that healthy, and when it comes to store brought ones that is usually the case as they're filled with funny additives, vegetable oils and a few preservatives — I even saw one recently where the first three ingredients were modified maize starch, cream and sugar, which was so bizarre, since when do you add cream to hummus?! (deliciouslyella.com)
Tried this using the bag of gluten free flour I had in the kitchen (I'm in Europe and we're light years behind on GF stuff: flour was made from maize starch, maize flour, thickener: locust bean gum). (artofglutenfreebaking.com)
Cornstarch — Cornstarch (also known as cornflour in Australia and the UK, and sometimes maize starch or maize) is the starch derived from the corn grain or wheat. (lazycatkitchen.com)