big, considerable, dramatic, enormous, great, high, huge, important, main, major, massive, powerful, profound, strong, tremendous
a high-impact message aimed at changing people's attitudes

discernible, measurable, noticeable, real, significant, substantial
A 1% rise is enough to have a measurable impact on economic growth.

limited, little, marginal, minimal, minimum, negligible
full
The industrial north of the country felt the full impact of the recession.

maximum
We'll show you how to dress for maximum impact at the all-important audition.

overall, total
growing, increasing
added
disproportionate
combined, cumulative
the cumulative impact of a series of damaging events

decisive
direct
Agriculture made a direct physical impact on the landscape.

immediate, instant, sudden
initial, short-term
lasting, long-term
broader, far-reaching, wider
It is important to appreciate the wider impact and implications of this proposal.

future, likely, possible, potential
beneficial, favourable/favorable, positive
adverse, catastrophic, damaging, destructive, detrimental, devastating, disastrous, heavy, negative, serious, severe
human
The severest human impact on the dolphins has been the loss of habitat.

personal
The personal impact of party leaders has been very important.

physical, visual
an attempt to reduce the visual impact of wind farms on the landscape

visceral
The film lacks the visceral impact of her previous work.

cultural, ecological, economic, emotional, environmental, financial, health, political, psychological, social
The environmental impact of power generation is being assessed.

achieve, create, exert, have, make
Variations in the interest rate will have an impact on the whole housing market.
You certainly made a big impact on Carter.

feel
The initial impact of the reforms will be felt most keenly in primary schools.

analyse/analyze, consider, examine, explore, investigate, monitor, study
We investigated the impact of new technologies on teaching methods.

assess, determine, estimate, evaluate, gauge, judge, measure, quantify
It is difficult to judge the likely impact of the changes on employment patterns.

underestimate
enhance, increase, maximize
alleviate, cushion, lessen, minimize, mitigate, offset, reduce, soften
We are trying to minimize the impact of price rises on our customers.

diminish, lessen, reduce, weaken
Listening to the speech through an interpreter lessened its impact somewhat.

lose
When peace returned, the hard-line message lost much of its impact.

resist, withstand
This section explores how mothers resist the impact of poverty on the health of their children.

be concerned about
appreciate, realize, recognize, understand
highlight
address
predict
reflect
Architecturally, these churches reflected the impact of the Renaissance.

under the impact of
Manufacturing fell sharply under the impact of the recession.

impact on, impact upon
to highlight the impact of technology on working practices

full
initial
asteroid, meteorite
the consequences of an asteroid impact

take
The front of the bus took the full impact of the crash.

feel
absorb
A well-designed sports shoe should absorb the impact on the 28 bones in each foot.

cushion, lessen, soften
Air bags are designed to soften the impact for crash victims.

survive, withstand
The crew of six may have survived the initial impact, but the whole plane went up in flames seconds later.

occur
Impact occurred seconds after the pilot radioed for help.

knock sb/sth …
The impact knocked him off balance.

speed, velocity
crater
Small meteorites have left impact craters all over the planet's surface.

on impact
The front of the car had crumpled on impact.

the moment, point, time, etc. of impact