Everyone knows you can find the meaning of English words in a dictionary. However, a dictionary can only provide the most basic answers. Dictionaries really only provide hints about each word, especially words that have different uses or completely different meanings. Some words change their meaning depending on their role or function in the sentence. For example, when used as a verb "live" means one thing and is pronounced in one way. When used as an adjective, "live" has both a different meaning and pronunciation.
Yesterday a student asked me about the word "civil." Because he had just taken a business training workshop, he knew about "civil rights" of workers that offer legal protection against discrimination. Civil rights are the topic of this cartoon. Civil rights in the U.S. became a common cause during efforts to reduce discrimination against people of color. More recently, civil rights have been extended to members of the military regarding their gender preference. Using "civil" in this way is only a specific application of the general usage.
The word civil forms the basis for "civilization." What is the difference between civilized and uncivilized people? Civilized people follow laws and social rules, try to be courteous and respectful to others, and to build sustainable societies. Even if people disagree completely, they can still debate their views with civil discourse instead of insulting, threatening, or attacking their opponent. People who act civilly believe in cooperation as well as competition. Civility is collaboration between people. Or from another view, being civil is just having good manners, acting civilized, not like a savage.
Civil rights then can be understood as the rights of an individual in a civilized society. The word has many other important meanings though. In the U.S., you can get married in a church or by religious means, or you can get married in a court by a judge or justice of the peace. In the second case, we call this a "civil" marriage to show that it was legally and socially sanctioned, but without any priest, minister, or other clergy presiding. The civil officer (judge) presides instead. If you don't choose a civil union, then you can have a "church" wedding.
Involvement of a judge and public court in civil marriages suggests that "civil" is an important part of the U.S. justice system. Our law is divided into two parts: criminal and civil. Criminal justice deals with crimes. Civil justice governs contracts between people or companies and resolves disputes between various parties when no crime is involved. Besides marriage, a kind of civil contract, civil courts are where lawsuits are filed and settled. Lately, many high tech companies have been suing each other over intellectual property (patents, etc.). These cases are all held in civil court since no crime is alleged.
"Civil war" is an oxymoron. (an oxymoron is a phrase that contradicts itself. Wars are anything but civil!) Yet we call wars that break out within one country civil wars because they are not wars with other countries. This year is the 150th anniversary of the American Civil War. This war was not at all civil and even though it was a long time ago, it killed more Americans than any other war before or since. So this phrase "civil war" is unintentionally ironic.
The dictionary will offer brief hints for these meanings, but fully understanding them is difficult, especially for non-native English speakers. Like many words, the deeper you look, the more you think about it, the more detail you see and appreciate. So dive in and really think about some words you already know. Do they have more than one meaning? Do their meanings change slightly in different expressions?