Twice from thrice' is a phrase that means to subtract one from three, resulting in two. It is a mathematical expression that can be used to describe a variety of situations, such as when a person has three items and needs to reduce it to two. It can also be used to describe a situation where a person has three options and needs to choose two. In either case, the phrase 'twice from thrice' is used to describe the process of reducing the number of items or options from three to two.