substantial

Substantially’ means a lot and the adjective ‘substantial’ means ‘large and important’.  It’s a popular word in business. It’s quite common to see ‘grow substantially’ and ‘substantial savings’ or ‘substantial investment’ for instance. The expression ‘a substantial minority’ is used when you want to say that a group of people are less than half the population, but still an important group that shouldn’t be ignored.

The company needs to reduce its costs sustantially if it is to remain competitive

We’ve invested substantial sums of money in the project.