Homonyms are words that are spelled the same and sound the same, but have different meanings. I know that may be different from what you thought. Many people think it simply means two words that sound the same, like time and thyme. These would, technically, be homophones, which may be spelled the same, or differently. There are further gradations from here, but it gets a little complicated.
So how do words end up being spelled the same and sounding the same, yet having different meanings? Usage, usually. How a word is used changes over the years (think of how “text” is now used as a verb), but often the root or origin of the words are the same. One of my favorite examples is the word reservation, which basically means a holding back. Restaurants can “hold back” a table for you, or you can “hold back” your approval of something by having reservations about it. Which leads us to the classic joke about the couple who arrived at the restaurant and were asked by the maître d’ if they had any reservations – to which they replied, “Oh, no. We’re sure we want to eat here.”
The word “magazine” has a long history of varied uses, many of which are now obsolete. Most of these stem from the word’s root meaning of “storehouse” or “repository.” It can refer to a place where goods or provisions are kept (especially military), a container for ammunition (as the magazine of a gun), or a large quantity of explosives. More obsolete references are to a stockpile of just about anything, to a portable container, and to an area or country rich in natural resources. At one time during the seventeenth century, the word denoted a ship that carried supplies. In more modern times it has referred to a television program in digest form on a particular topic or, most commonly, a periodical of assorted articles. A magazine in this sense is basically a small storehouse of ideas of interest to a particular group – sometimes “explosive.” I suppose this means you could refer to a warehouse where periodicals are stored as a “magazine magazine.”
Today, a mixture of nautical references and literary names that I hope you won’t deep six.
This slang phrase meaning to discard something originates from the practice of burials at sea, which are done at a depth of six fathoms. The term was popularized during the Watergate trials of the early 1970s, when lots of documents were “deep sixed.” (Watergate, of course, also gave us the suffix “-gate” to denote scandals, taken from the name of the hotel where the scandal started).
While we’re on the subject of nautical terms, Mark Twain, a.k.a. Samuel Clemens, took his pen name from such a term. Clemens worked as a steamboat pilot on the Mississippi, where they would cry out “mark twain” to denote a river depth of two fathoms. Thus one of the most famous names in literature was born. While it is tempting to think that another literary giant, Charles Dickens, lends his name in a reverse fashion to phrases such as “hurt like the dickens” or “give someone the dickens,” the phrase has nothing to do with him. It was around hundreds of years before he was born, and is a euphemism for the devil.