When you dial a number on your telephone, you're barely conscious of the intricate history of the word. The verb dial, naturally, goes back to the good ole days when to call someone you actually had to spin a rotating dial to input the number of that person. This telephone dial was first attested as a word in 1879, and the word dial itself carried connotations of circular motion since it was used to discuss sundials. Since sundials tell the time of day, it is unsurprising that the word dial traces to Latin dialis, which meant "concerning the day". This is a conjugated form of the word diem (as in carpe), from Proto-Italic djem. Though etymologists are never quite sure about these things, djem is reconstructed as originating from the Proto-Indo-European root dyem, still "day". The noun-to-verb switch we see here is fairly common, and it is called verbification, a subordinate concept of anthimeria, when a part of speech changes.
Adam Aleksic, a freshman studying linguistics at Harvard University, has been described as the internet's sixth most famous etymologist. He has disturbing interests in words, vexillology, geography, board games, limericks, and law, and he loves writing about himself in the third person.
The Etymology Nerd