The phrase "extremely tightly" is correct and usable in written English.
You could use it to emphasize how firmly something is held in place, for example: "She held the box closed extremely tightly to prevent anything from spilling out."
The cruise line business is already extremely tightly regulated.
The legislation is extremely tightly drawn, and efforts to prove it unconstitutional have so far failed.
After the petticoats came a white embroidered blouse, a red skirt and then a wide waist band which was pulled and tied extremely tightly.
Derham believes the line-up shows a good spread of fiction, from Hazzard's The Bay of Noon ("I was shouted down when I said this is what ought to be called chick lit, but it's very appealing to a female audience"), to the "extremely tightly written, bleak, sharp, spiky Muriel Spark".
It turned out to be an extremely tightly plotted affair, the storytelling as flab-free as the athletic cast, full of twists, surprises, and such never-before-seen-on-TV things as a bridge made of corpses and a gay couple (Agron and Nasir, dubbed Nagron by fans) who make it to the end without anyone commenting on their sexuality.
It's so weird to see you guys!" When Leah proceeded to offer these people a round — "No, you sit, we'll get" — Natalie Blake panicked, her budget being extremely tightly managed, with no space for rounds of drinks for Crusties to whom she had never before spoken in her life.
Of particular concern are so-called 'item numbers' which are extremely popular, tightly choreographed and often sexually provocative musical performances which routinely appear in Bollywood films.
One factor preventing the worlds of Nashville and Broadway from joining forces is that each has always been extremely clannish and tightly knit.
As new data emerges, it is becoming clear that the diversity of downstream functions observed result from extremely intricate and tightly regulated mechanisms that control NFκB activation in a cell-, stimulus-, and temporal-specific manner.
Since these methods can detect tens of copies of a gene, expression levels below this detection limit are indicative of either no expression within any of the investigated tissues, or of an extremely localised or tightly regulated expression.
The failure to detect expression within various tissues pointed to an extremely localised or tightly, developmentally regulated expression with a unique spatio-temporal role in human brain development, independent of an interaction with DAO [ 36].
