The phrase "a terribly short" is correct and usable in written English.
It can be used to describe something that is very brief in duration or length, often conveying a sense of disappointment or surprise.
Example: "The meeting was a terribly short affair, lasting only ten minutes."
Alternatives: "a painfully brief" or "an alarmingly short".
The makeshift rubber Jane had been playing with had all kinds of problems: it didn't adhere to enough surfaces, it had a terribly short shelf-life, and it was too high maintenance to make a successful commercial product.
I think this is a terribly short amount of time to get something done.
"There was such faith in 'shock and awe' it led to the conclusion it had to be a terribly short war," he said.
That's how Dennis makes all of his work though, and if you take the time to look closely at the hundreds of strokes he had to make with his chisel to create his stuff, you will realize that you have no patience and a terribly short attention span compared to the guy who made the gigantic wolfbat (a recurring character in Dennis' work) sitting in front of you.
The suffering was compounded for Muscovites and other residents of western Russia, for whom the summer is a sweet, though terribly short, respite after spending nine months or more putting up with snow and ice.
In the 1980s, Malcolm Wallop, a Republican senator from Wyoming, blasted the agency for spending money on super computers, saying that it should be investing in weapons—a criticism that ended up being terribly short sighted given the current importance of computing to almost all weapons.
Time is terribly short, but a strike can still succeed".
Garlic may be available year-round, but the season for young garlic is terribly short, only a few weeks in spring and early summer.
"Time is terribly short, but a strike can still succeed," he said, advocating Israeli action specifically.
I hear all of this in a particularly Dame Maggie Smith tone: ''I was terribly short this weekend.'' You did a lovely thing, you tried to respond graciously and there was no insult in your offer.
Because of economic constraints and the numerous commitments dictating the life of any academic, the project duration was fixed at 9 days a terribly short time for such an ambitious task.
