Over and Under
A friend of mine, Mr David Alterman, has recently been enquiring about the words "over" and "under" and the range of words in which they are suffixes. In their roles as prepositions or adverbs they are simple antonyms. That's straighforward enough. "Over" means above, higher or more than; "under" means below, lower or less than. But when we come to compound words the story is not so clear. In many cases, indeed, they are opposites – if something is "underdeveloped" it is not developed enough, if
"overdeveloped" it is developed too much. On the other hand, "overtake" and "undertake" are not opposites. It is a little difficult to pinpoint what work the prefix is actually doing in those words.
Moreover, under- does not always connote lack, insufficiency or subordination. Sometimes it suggests something more like strengthening or supporting: "underpin"; "undergird"; "underwrite". Perhaps "understand" belongs to this group too? "Over", meanwhile, does not always suggest excess or on-topness. There are words in which it connotes spread or extent – as in "overall" or "overgrown" (which, as Dave points out, makes an odd pairing with "undergrowth").
I don't have a theory for why these words have acquired such diverse connotations. All I can say is that they are venerable words, found in Old English. Under was exactly the same word in Old English, while over was written "ofer". (I remember learning the word "ofermode" from the 10th century Anglo-Saxon poem The Battle of Maldon, meaning rashness or overconfidence). So they have had plenty of time over the centuries to expand their semantic reach.
Dr Brandon Robshaw lectures for the Open University in Philosophy, Creative Writing and Children’s Literature. He has written several children’s books including a philosophical YA novel, The Infinite Powers of Adam Gowers. He and his family starred in BBC2’s Back in Time for Dinner. You can find his website here.