The phrase "a significant line" is correct and usable in written English.
It can be used when referring to an important or meaningful statement, quote, or boundary in various contexts, such as literature, art, or discussions.
Example: "In her speech, she drew a significant line between personal beliefs and professional responsibilities."
Alternatives: "an important line" or "a crucial line".
"Every human being is a collection of selves," is a significant line in the TV adaptation.
When the article appeared, Hatton seems to have realised he had crossed a significant line.
Payne said the possibility it was a racially motivated attack was "a significant line of inquiry" and a large number of detectives were working on the case.
A deal is a deal, so it's no surprise that the place often has a significant line; given the shaky state of the economy, there's bound to be no slack in demand.
MAN IN THE MIDDLE Last year, after the final event before the Tour Championship, Brandt Snedeker thought that he ranked sixth in the point standings, one rung below a significant line of demarcation.
His appointment will therefore be seen as a significant line in the sand for a Leicestershire club who have become a basket case in recent seasons, the first county to go through two entire summers without winning a Championship match since Northamptonshire in the 1930s.
These cells, besides inter cell line variability, exhibited a significant intra cell line variation.
WuXi, founded in 2000, gained a significant new line of business when it acquired AppTec Laboratory Services of St. Paul in 2008 for about $151 million.
Might some future generation take it further than Singer wants to go? Might some say there's no morally significant line between a newborn and a 3-year-old?" "Sure.
A significant selection line x soil treatment interaction was observed, with shortest developmental times for mites with matching selection line-treatment combinations (Fig. 2A).
Additionally, spore load differed between host lines and parasite isolates, and was generally lower in coevolved hosts, but there was also a significant host line × parasite isolate interaction.
