English has a whole category of words called “contronyms” — words that have opposing definitions, such as “cleave” meaning both join and cut apart,”sanction” meaning both allow and prohibit, and, to the consternation of many of us, “literally” meaning both actually and figuratively. (See more contronyms at Mental Floss and Daily Writing Tips.)

But English also has descriptive phrases that consist of seemingly opposite adverbs + adjectives, such as:

• This cake is awfully good.
• Her sister is terribly nice.
• This hugely insignificant change won’t affect anything.
• These immensely small subatomic particles were discovered only recently.
• The blue shirt is a little big on you.
• That couch the Bundys bought at the flea market is pretty ugly.

I’m thinking here about phrases used without irony, sarcasm or poetic license. I wondered whether this phenomenon has a name, so I went digging (figuratively) to find out. I looked in books, I looked online, I asked around.

“Antiphrasis” seems that it would be something similar, but it’s a joking or ironic use of a word to mean the opposite, like someone calling an increase of 0.001 percent “gigantic” or an action hero telling the villain “you might feel a little sting” right before blasting him. So, nice to know, but not what I was looking for.

But then I got to a phenomenon called “semantic bleaching” (a concept credited to 19th-century linguist Georg von der Gabelentz), which in linguistics means that part of a word’s original meaning – usually an extreme – gets “bleached” out as the word takes on a more general sense.

Take “terrible” as an example: as an adjective, it still means not just bad, but really bad (“a terrible movie”). But as an adverb, the “bad” part has been bleached out, so only the intensifying part of the meaning remains, so to be “terribly nice” or “terribly talented” is a good thing. This is also the case with “awfully,” “hugely,” “immensely” and similar adverbs, as well as non-adverbs like “awesome” (which is often used for things that are far, far less than awe-inspiring) and even “love” (as in, “I love this commercial” or “I love it when the elevator’s right there”).

“Pretty” is interesting because as an adverb it can mean both “sort of” and “a lot,” depending on context. “Breakfast at the new cafe is pretty good” is not exactly a ringing endorsement. Contrast that with “40 below is pretty cold,” which is intended to emphasize that it is indeed very cold. (Interestingly, the word’s Old-English root means “tricky” or “crafty,” so there’s already been significant meaning shift with “pretty.”)

Pretty awesome, right?