A Reader's Companion III, 3,500 words and phrases avid readers should know is the third in a trilogy of books on words. Some of the words are included in this edition because they are similar like immanent, which means existing within or inherent in something, eminent which means of superior position and imminent which means about to happen. A phoneme is the smallest speech sound that distinguishes one word from another that carries the words meaning, so there are subtle phonemes that distinguish immanent, eminent and imminent. Most think a sieve is a utensil but in reality it is any device used for separating wanted and unwanted material. Contrasting words in this edition include pecunious, which means having money and impecunious which means having no money. An astronaut is one trained to travel and perform tasks in space is contrasted with intranaut who is an individual who explores their own mind in search of meaning. Pertinacity, which means to be resolute in purpose is contrasted with impertinent which means to be brash. Some root word derivations are included like illicit, which means illegal and licit which means legal. Finally, some words describe different relations. In marriage most know monogamy means being married to only one person at a time and perhaps polygamy which means having more than one spouse at the same time. But there is also polyandry or having more than one husband at the same time, exogamy which is the custom of marrying outside one's social group and endogamy which is the custom of marrying a member of one's social group. This is a good book for avid readers who want to improve their vocabulary.