Englishfor English speakers
erratic
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adjective
(= fickle, mercurial, quicksilver)
liable to sudden unpredictable change
erratic behavior
fickle weather
mercurial twists of temperament
a quicksilver character, cool and willful at one moment, utterly fragile the next
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adjective
(= planetary, wandering)
having no fixed course
an erratic comet
his life followed a wandering course
a planetary vagabond
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adjective
(= temperamental)
likely to perform unpredictably
erratic winds are the bane of a sailor
a temperamental motor; sometimes it would start and sometimes it wouldn't
that beautiful but temperamental instrument the flute
— Osbert Lancaster
operation
Noun
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An operation is a medical process, often opening the human body.
The doctors performed the operation in three hours.
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An operation is an action of a group of people working for a goal (often military).
The Army operation was a success.
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An operation is part or all of a business. small(often plural)/small
The company's East Coast operation was bigger than its West Coast operation.
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An operation is a symbol that is used to perform a specific operation (addition, subtraction, multiplication or division) in maths.
The plus symbol is used to perform a specific operation in maths which is addition.