zero

I. ze‧ro¹ /ˈzɪərəʊ $ ˈziːroʊ/ BrE AmE number (plural zeros or zeroes)
[Date: 1600-1700; Language: French; Origin: zéro, from Arabic sifr 'empty, nothing']
1. the number 0 SYN nought British English:
Make x greater than or equal to zero.
2. the point between + and – on a scale for measuring something, or the lowest point on a scale that shows how much there is left of something:
The petrol gauge was already at zero.
3. a temperature of 0º on the Celsius or Fahrenheit scale
above/below zero
It was five degrees below zero last night. ⇨ ↑absolute zero, ↑sub-zero
4. none at all, or the lowest possible amount
sb’s chances are zero (=they have no chance of success)
Mike’s chances of winning are virtually zero.
From 1971 to 1976 West Vancouver experienced zero population growth.
• • •
THESAURUS
▪ zero the number 0. Also used when saying there is nothing at all: A million is written as one followed by six zeros. | a temperature of zero degrees | Our chances of success are virtually zero.
▪ nil British English zero - used especially in the results of sports games: United won the game three-nil. | In rural areas, employment opportunities are almost nil.
▪ nought British English spoken zero – used in calculations and figures: It has increased by nought point seven five per cent (=0.75%).
▪ O used to say the number 0 like the letter O: The code for Oxford is 0 one eight six five (=01865).

Oxford Advanced Learner's Dictionary

zero

zero [zero zeros] number, verb [ˈzɪərəʊ] [ˈzɪroʊ] [ˈziːroʊ]

number
1. (pl. zeros) (BrE also nought) 0

• Five, four, three, two, one, zero… We have lift-off.

2. a temperature, pressure, etc. that is equal to zero on a scale
• It was ten degrees below zero last night (= −10°C).

• The thermometer had fallen to zero.

3. the lowest possible amount or level; nothing at all
• I rated my chances as zero.
• zero inflation
Word Origin:
early 17th cent.: from French zéro or Italian zero, via Old Spanish from Arabic ṣifr ‘cipher’.

Derived: zero in on somebody

Cambridge Advanced Learner's Dictionary

Cambridge Advanced Learner's Dictionary - 4th Edition

zero / ˈzɪə.rəʊ / / ˈzɪr.oʊ / number ( plural zeros )

A2 [ C or U ] (the number) 0; nothing:

Five, four, three, two, one, zero.

The number one million is written with a one and six zeros.

Heavy rain has reduced visibility almost to zero (= its lowest point) .

B1 [ U ] on a set of numbers for comparing temperature in degrees Celsius, the level of temperature at which water freezes:

The temperature is expected to drop to ten degrees below zero tonight.

Collins Advanced Learner’s English Dictionary

zero

[zɪ͟əroʊ]
zeros, zeroes (plural & 3rd person present), zeroing, zeroed
1) NUM Zero is the number 0.
  Visibility at the city's airport came down to zero, bringing air traffic to a standstill.
  ...a scale ranging from zero to seven.
  Syn:
  nought, nil
2) N-UNCOUNT Zero is a temperature of 0°. It is freezing point on the Centigrade and Celsius scales, and 32° below freezing point on the Fahrenheit scale.
  It's a sunny late winter day, just a few degrees above zero...
  That night the mercury fell to thirty degrees below zero.
3) ADJ You can use zero to say that there is none at all of the thing mentioned.
  This new ministry was being created with zero assets and zero liabilities.
  ...zero inflation...
  His chances are zero.

Merriam-Webster's Advanced Learner's Dictionary

¹ze·ro /ˈziroʊ/ noun, pl ze·ros also ze·roes
1 : the number 0

[count]

• One million is a one with six zeros [=(Brit) noughts] after it.

[noncount]

• Two minus two equals zero.
2 [noncount] : the temperature shown by the zero mark on a thermometer
• It's supposed to fall below zero tonight.
• The temperature is 10° above/below zero.
- see also absolute zero, subzero
3 [noncount] : nothing at all
• They are working to reduce the mortality rate to zero.
• Her contribution to the project was close to zero. [=she did almost nothing on the project]
• The car can go from zero to 60 in 10 seconds. [=from not moving at all to going 60 miles per hour in 10 seconds]
• (informal) I know zero [=nada, zilch] about fixing computers.
• You'll have to start from zero [=from scratch] if you can't find your notes.
4 [count] informal : a person who is not important, interesting, popular, etc. - usually singular
• Her new boyfriend's a real zero. [=loser]