Englishfor English speakers
wasteful
—
adjective
(= uneconomical)
inefficient in use of time and effort and materials
a clumsy and wasteful process
wasteful duplication of effort
uneconomical ebb and flow of power
—
adjective
tending to squander and waste
—
adjective
laying waste
when wasteful war shall statues overturn
— Shakespeare
expense
Noun
—
An expense is something for which you spend money.
Food is a huge expense for many people around the world.
—
An expense is an amount of money that you spend.
If your income is less than your expenses, you have a serious problem.
The company paid all of his expenses when he was in Shanghai.
The building was repaired at great expense.
—
If you do mathx/math at the expense of mathy/math, mathx/math hurts mathy/math because it makes mathy/math have less money, less time, less social status, etc.
She often makes jokes at her own expense.
We have to decide whether safety at the expense of freedom is worth the cost.