reversal

Everyday

1. A reversal is a change to the opposite direction, order or result. tree →
2. A reversal can be a sudden change of fortune, often from good to bad. tree →
3. (law) A reversal is when a decision is changed by a higher authority. tree →

In the lessons

In maths, reversal can mean undoing an operation (inverse operations, like reversing ×2 with ÷2) or reversing the order of digits. In science, a reversal of a process (melting then freezing) shows a reversible change. In stories and sports, a reversal is a big turnaround. Phrases: "a complete reversal", "role reversal", "reversal of fortune", "a policy reversal".

Examples

• The team made an amazing reversal in the second half. tree →
• In the play there was a role reversal: the children were in charge and the parents obeyed. tree →
• The new rule was a reversal of the old one. tree →
• The reversal of 47 is 74. tree →
• Freezing melted ice again is a reversal of the change. tree →
• (law) The higher court ordered a reversal of the decision. tree →
• Losing his job was a sad reversal of fortune. tree →

Note

Countable: a reversal, reversals. Verb: reverse; adjective: reversible. In maths: reversing the digits of 52 gives 25, and 52 − 25 = 27 (a multiple of 9, true for every two-digit number). Reversing an operation is using its inverse.

In Jewish tradition

In Sefer Yetzirah writing it means swapping or turning Hebrew letters around by set rules.

Interpretation. Kabbalists study such rules as a way to find deeper meanings in the letters of the Hebrew alphabet.

Examples

• The Kabalistic principles involved in the reversal of Hebrew letters, and their substitution by others, on definite schemes, should also be studied and borne in mind. (Sefer Yetzirah, Westcott 1893) tree →

Note

Countable: a reversal, reversals. Verb: reverse; adjective: reversible. In maths: reversing the digits of 52 gives 25, and 52 − 25 = 27 (a multiple of 9, true for every two-digit number). Reversing an operation is using its inverse.