One Word Substitution

A jockey is a person who rides in horse races, especially as a profession.

A philatelist is a person who studies or collects postage stamps.

An encyclopedia is a book or set of books giving information on many subjects or on many aspects of one subject.

 A man whose wife is dead is known as a widower. Hence, widower is correct.

Illegitimate refers to a child born to parents who are not married to each other.

Portable describes something that is easily carried or moved. Edible means fit to be eaten, potable means fit to be drunk, and bearable means able to be endured.

A draw is a contest or game that ends with no winner. Abandoned means left behind, postponed means delayed, and obsolete means no longer in use.

Extempore refers to something spoken or done without prior preparation. Elocution refers to the skill of clear and expressive speech, not the preparation level.

Unanimous means fully in agreement. Anonymous means having no known name, and obsolete means outdated.

An honorary position is one held without a salary, often as a mark of respect. Voluntary refers to doing something by choice, not necessarily without pay.

A polyglot is a person who knows or uses several languages. A linguist is a person who studies linguistics, the science of language.

Inaudible means impossible to hear. Audible is the opposite, and ineffaceable means impossible to erase.

An autopsy is a post-mortem examination of a body to determine the cause of death. A biopsy is the removal of tissue from a living body for examination.

A platitude is a remark or statement that has been used too often to be interesting or thoughtful. An epigram is a pithy saying or remark expressing an idea in a clever way.

Ornithology is the scientific study of birds. Philology is the study of language in oral and written historical sources.