adverse
- 01 C1 Advanced
harmful, negative, or preventing success.
unfavourable or antagonistic in effect; acting against one's interests or welfare.
Simple“The match was cancelled due to adverse weather conditions.”
In context“The pharmaceutical company was forced to halt the clinical trial after several participants reported adverse reactions to the new medication.”
UsageCommonly collocates with 'weather', 'conditions', 'effects', and 'reactions'.
Teacher's tipLearners frequently confuse this with 'averse'. Remind them that 'adverse' usually describes things or situations, while 'averse' describes a person's feelings (e.g., 'risk-averse').
PitfallThe medicine had averse side effects. The medicine had adverse side effects.Do not confuse 'adverse' (harmful conditions) with 'averse' (a person's strong dislike or opposition to something).
SynonymsAntonyms - 02 C2 Proficiency
facing the opposite way or being on the opposite side.
positioned in an opposite direction or confronting; often used in technical or botanical contexts.
Simple“The leaves grow in an adverse position along the stem.”
In context“The researcher noted the adverse placement of the sensors, which resulted in conflicting data streams during the initial phase of the experiment.”
Usage adverse effects · adverse health
“Ed Wollaston, director of global response at Ambrey, said the “extremely challenging situation” had been complicated by adverse weather from the annual Khareef monsoon.”
“A class of synthetic chemicals that take an extremely long time to break down, per- and polyfluoroalkyl substances (PFAS) face rising restrictions worldwide due to adverse health effects.”
First attested around 1374, from Old French avers (French adverse), from Latin adversus (“turned against”), past participle of advertere, from ad- (“to”) + vertere (“to turn”). See also versus.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.