efficient and effective

effective

ef‧fec‧tive S2 W1 /ɪˈfektɪv/ adjective
  [Word Family: noun: effect, effectiveness ≠ ineffectiveness; adjective: effective ≠ ineffective, effectual ≠ ineffectual; verb: effect; adverb: effectively ≠ ineffectively]
 1. successful, and working in the way that was intended OPP ineffective:
   • The cheaper drugs are just as effective in treating arthritis.
   • the painting’s highly effective use of colour
   • Training is often much less effective than expected.
   • the most effective ways of reducing inner city congestion
  REGISTER
   In everyday English, people usually say that something works (well), rather than say that it is effective:
   ▪ • The cheaper drugs work just as well.
 2. [no comparative, not before noun] if a law, agreement, or system becomes effective, it officially starts
  effective from
   • The cut in interest rates is effective from Monday.
 3. [no comparative, only before noun] real rather than what is officially intended or generally believed:
   • The rebels are in effective control of the city.
 —effectiveness noun [uncountable]
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COLLOCATIONS

■ adverbs

   ▪ extremely/highly effective • The company launched a highly effective advertising campaign.

■ nouns

   ▪ an effective way • What’s the most effective way to control crime?
   ▪ an effective method • Exams are not the most effective method of assessing students’ abilities.
   ▪ an effective means • Is reducing the speed limit an effective means of reducing accidents?
   ▪ effective action • The police must take effective action to protect the public.
   ▪ an effective solution • The most effective solution to traffic congestion is to build more roads.
   ▪ an effective treatment • Antibiotics are still the most effective treatment for this disease.
   ▪ an effective system • The country has a simple but effective welfare system.
     • • •

THESAURUS

   ▪ successful achieving what you wanted, or having the effect or result you intended: • He applied for a visa three times and in the end he was successful. | • The treatment was successful. | • It was a highly successful campaign.
   ▪ effective having the effect or result that was wanted - used especially about treatments, drugs, or methods: • The drug is effective against a range of diseases. | • We still haven't found an effective way to solve the problem.
   ▪ victorious successful as a result of winning in a game, election, war etc: • the captain of the victorious team | • She emerged victorious in the second round of voting.
   ▪ promising likely to be very successful in the future, used especially about someone who is good at a job, sport, art etc: • a promising young athlete | • He gave up a promising career in banking.
   ▪ thriving very successful – used about a company, industry, or organization that is doing well at a particular time: • The area has a thriving tourist industry. | • The school is thriving academically.
   ▪ booming extremely successful – used about an economy, or when business or trade is increasing: • the booming economy in China | • Business is booming.