Both words refer to making an idea or thing clear or comprehensible. Explain emphasizes the act of giving a complete account of something. After a teacher explains a concept, she might then quiz students to see how much they have understood. Whereas you can explain something badly and then try to explain more fully or in more detail, elucidate implies that clarity is accomplished (whether or not the reader or listener is able to see it). Elucidate refers to making something clear or more clear for others, as if shining a light on or through it—a speaker, a book, a series of studies, or research results are typical subjects of elucidate. Typical objects include a mechanism, relationship, role, or structure—concepts or processes more complex, perhaps, than those that can be exhaustively explained.

Both these verbs refer to the act of capturing information in writing or other media, with fidelity to objective fact, in order to preserve it. You might record your daily thoughts in a video journal or record lab results in a spreadsheet. Strictly speaking, to chronicle is to record events in chronological order. If you chronicle daily life in the town you live in, you would be recording what you experienced or witnessed daily in a form more like a list than a narrative. These days, the verb is more loosely used—it’s more likely a book or film that chronicles, not a person, and a book that chronicles a journey or history probably wasn’t written as the events occurred, although a blog may have been.

Failure refers to something that is not successful: The party was a big failure; I was disappointed by the failure of my idea. A failure is hard to take, but there are worse things—like a fiasco, which refers to a usually public failure so complete that it is disgraceful, humiliating, and sometimes bordering on the ridiculous. A wedding reception at which the vegetarian option contains lamb, the air conditioning breaks down, and the newlyweds get into a screaming match and leave in separate cars would be a fiasco. Some of the most typical phrasing found with fiasco is also found with words like “scandal,” “controversy,” and “affair.” For example: this whole wiretapping fiasco could have been avoided; Remember last year’s state fair fiasco involving the goat milk judges?