What is a threshold? Definition and meaning

The word threshold can mean the level at which something is affected by a particular rule or belongs in a particular class, or the level of money earned or income above which individuals or businesses have to pay tax, or must pay a different rate of tax.

It can also be the area at the bottom of a doorway or door frame that we need to cross in order to enter or leave a room or a house, as in “The groom carried the bride over the threshold.”

In Australia, you do not have to pay tax on the first $18,200 of your income. That is your tax-free threshold. The word also means the area on the floor between the inside and outside of a room or house, at the bottom of a doorway.

Training Threshold: the minimum amount of exercise that a person must complete to help improve his or her physical fitness. If it is not achieved, the exercise is not considered to be an effective one.

Income Tax Threshold: the income level at which an individual starts paying income tax. This is called the personal tax allowance in the UK, the standard deduction and personal exemption in the US, the basic personal amount in Canada, and the tax-free threshold in Australia.

In the United States, the personal exemption increased from $3,950 to $4,000 in 2015. People lose at least part of their exemptions if their adjusted gross income exceeds $154,950 for a married person filing a separate return, $258,250 for a single person, $284,050 for a head of household, and $309,900 for married couples filing jointly.

In the UK, a person’s personal allowance is £11,000.

Pain ThresholdPeople with a high pain threshold can withstand a greater severity of pain compared to an average person.

The majority of countries have a tax-free threshold, which is higher if the main earner is married. However, as more and more families have both parents in jobs, in some parts of the world couples may find themselves financially better off if they do not get married.

Interest-Free Threshold: if you have an overdraft and stay within the agreed limit, you do not have to pay interest. Many banks offer this facility. NatWest, a British bank, says: “However, if the amount you overdraw under an arranged facility exceeds these thresholds, interest on the overdrawn balance will be added.”

The word can also mean ‘on the verge of’ or ‘reaching the point of’, as in “We are on the threshold acquiring the most devastating weapons in history,” or “We are on the threshold of an age of space travel.”

Pain Threshold

Threshold is used to describe the point at which an outside stimulus – temperature or pressure – activates pain receptors and produces a sensation of pain. If you have a low pain threshold you experience pain much sooner and faster than individuals with higher ones.

German scientists are teaching robots to feel pain, they say it is good for them. If a robot has a limitless pain threshold – is unable to feel pain – it is less likely to avoid potential damage to its electronics, motors and gears.

History of threshold

Alfred the Great (849-899), who was King of Wessex (in England) from 871 to 899, translated the Roman philosopher Boethius’ De Consolatione Philosophiae. In that Old English translation, which was done in 888, the word appears as ‘þeorscwold’ (the first letter called a thorn was pronounced as the ‘th’ in the word ‘thin’).

Etymologists – people who study the origins of words – do not know where the Old English word ‘þeorscwold’ came from. It was probably related to ‘threscan’, an Old English word from which we get the meaning ‘to thrash’, and ‘to separate seeds from a harvested plant using a machine or tool’.