drastic
adjective
uk/ˈdræstɪk/ ussevere and sudden, or having very noticeable effects:
He is not under pressure from his own electorate to do anything drastic.
a drastic decline/drop/reduction in sth
take drastic action/measures/steps The company is taking drastic action to reduce its debt by $14.3 billion.
drastic changes/cuts in sth
drastically
adverb
The manufacturer will also report drastically reduced turnover of £3.5m in the year to this month.