›the most important part of something, providingsupport for everything else: the mainstay of sthAntibiotic therapy is the mainstay of treatment for many infections.Cattle farming is the mainstay of the country's economy.
Highly delighted, bitterly disappointed, ridiculously cheap: adverbs for emphasis.
by Liz Walter,
October 22, 2014
We often make adjectives stronger by putting an adverb in front of them. The most common ones are very and, for a stronger meaning, extremely: He was very pleased. The ship is extremely large. However, we don’t use very or extremely for adjectives that already have a strong meaning, for example fantastic,