depletion, irrigation, severity, conservation, catastrophe: meanings and examples

Learn these 5 words from Advanced set 7. Each entry includes a definition, example sentence, pronunciation, and synonyms. Use the interactive cards above to practice them.

1. depletion · noun/dəˈpliʃ(ə)n/

   the condition of decreasing in amount or number

   Nitrous oxide is the largest cause of ozone layer depletion, which has an adverse impact on human health and the environment.

   Synonyms: decrease, deficiency, reduction

2. irrigation · noun/ˌɪrəˈɡeɪʃ(ə)n/

   the act of supplying land with water

   Some areas in big cities have lawns watered by inefficient irrigation systems, which strains the limited water supply of the country.

   Synonyms: watering

3. severity · noun/səˈvɛrədi/

   the degree to which something is serious, harsh, or intense

   The severity of damage caused by a natural disaster is evaluated by the number of people affected compared to the statistics of previous occurrences.

   Synonyms: intensity

4. conservation · noun/ˌkɑnsərˈveɪʃən/

   careful management of the environment and of natural resources for preservation

   The conservation of wildlife is an integral part of forest management.

   Synonyms: preservation

   Origin: late Middle English: from Latin conservatio(n-), from the verb conservare (see conserve)

5. catastrophe · noun/kəˈtæstrəfi/

   an event that results in great loss and ruin

   The worst environmental catastrophe in Earth’s history is believed to have occurred 66 million years ago, when an estimated 70 percent of all species were killed by an asteroid.

   Synonyms: disaster, tragedy

   Origin: mid 16th century (in the sense ‘denouement’): from Latin catastropha, from Greek katastrophē ‘overturning, sudden turn’, from kata- ‘down’ + strophē ‘turning’ (from strephein ‘to turn’)