The phrase "a certain insecurity" is correct and usable in written English.
It can be used to describe a specific feeling of uncertainty or lack of confidence that someone may experience in various contexts.
Example: "Despite her many accomplishments, she often felt a certain insecurity about her abilities in the workplace."
Alternatives: "a particular insecurity" or "a specific insecurity".
"What was nice about Bardot is that she kept a certain insecurity," Vandeperre says.
He seems to feel that insisting on the vanguard angle betokens a certain insecurity, an effort to raise puppetry's status, buy it a fur coat.
Mr. Philbin said that for a long time he felt a certain insecurity about what his talent really was, since he wasn't truly a singer, dancer or comic.
Maybe some of this emperor's new clothes syndrome (ENCS) links to emerging subjects that display a certain insecurity and therefore insist on fancying up their credentials.
But for all the talk of their special qualifications, many of these former opposition leaders still betray a certain insecurity about their future.
Mr. Russell Beale does what he can about this, suggesting a certain insecurity behind the posturing and even finding a touch of pathos in George's devotion to Suzanne Burden's chillingly exquisite Mrs. Fitzherbert.
He expresses perplexity at what he deems a "certain, extraordinary insecurity" on Kissinger's part, which he traces back to Kissinger's origins as a young Jewish refugee from Nazism.
The mob is often portrayed as an oasis of tradition, a society with a clear vision of authority and fraternity, a refuge for men of sentiment, a place where a certain social insecurity is veiled by the tightness of family and the threat of force.
Of course, you don't have to travel to St Barts to see evidence that a certain type of insecurity increases in direct proportion to one's wealth.
Blurryface "represents a certain level of insecurity," Joseph has said, and he sings in character as Blurryface for part of the live set, smearing his face and hands with black paint.
