The phrase "a massive chunk" is correct and usable in written English.
It can be used to describe a large piece or portion of something, often in a figurative sense.
Example: "After the meeting, we received a massive chunk of feedback from the clients that we need to address."
Alternatives: "a large portion" or "a significant amount".
It's a massive chunk of money in a somewhat anemic fundraising environment.
They really need to take a massive chunk off to make any difference but they won't.
A massive chunk of Lorraine coal is a reminder of the hardships and dangers of pit life.
Almost all big movies now open on 2,000 or more screens, hoping to recover a massive chunk of the budget in the first week of release.
Back in the mid-1990's, a less cautious tree surgeon had lopped off a massive chunk of the tree, right up near the top.
Certainly, they've taken a huge share of the popular vote and, significantly, have demonstrated that they can take a massive chunk out of Labour's traditional northern vote.
With the city council's approval, he jettisoned an unpopular car tax, stripped transit workers of their right to strike, and outsourced a massive chunk of Toronto's garbage collection.
The more senior submariner allegedly told McNeilly that the French vessel "took a massive chunk out of the front of HMS Vanguard" and grazed the side of the boat.
The St . PaulPioneer Press devoted a massive chunk of its front page to it; the New York Times ran a somewhat smaller version that nonetheless dominated the page.
But they just got even weirder: According to research published Monday in the Proceedings of the National Academy of Sciences, tardigrades get a massive chunk of their DNA from other organisms.
Trust the reader (you don't need footnotes such as "the poet I refer to here is John Clare" or "Aung San Suu Kyi is currently held under house arrest in Burma"), but don't trust them too much: don't pick for your epigraph a massive chunk of Heidegger in the original German.
