heavy

heavy going difficult or boring to deal with.

2012New Statesman Non-academic readers may find Robert Holland's latest volume heavy going at times but it will remain the definitive account of Anglo-Mediterranean history for years to come.

heavy hitter: see big hitter atbig.

heavy lifting hard work; great, especially non-physical effort. chiefly US

2019Observer Du Sautoy is open about his doubts when evaluating the new A[rtificial] I[ntelligence] … As he sees it, the creative heavy lifting is often being done by the programmer or the audience, and not the program itself.

the heavy mob a group of strong or violent criminals or bodyguards. British informal

heavy on using a lot of.

1984Studs TerkelThe Good War We were heavy on the Italian feeling in America. We were more Italian than Italians.

make heavy weather: seeweather.