decade

Everyday

1. A decade is a period of ten years. tree →
2. A decade is also a group of ten, like ten beads on a rosary. tree →

In the lessons

In maths and history lessons it is used to measure time: one decade = 10 years, two decades = 20 years. It tells the reader a long time has passed. Phrases: for decades, over the past decade, a decade ago, the next decade.

Examples

• A decade is ten years. tree →
• My grandparents have lived in this house for five decades. tree →
• The old tree has grown a lot over the last decade. tree →
• Two decades equal twenty years. tree →
• My mum hasn't seen her cousin for a decade. tree →
• The town has changed a lot in the past decade. tree →
• If a tree grows 30 centimetres a year, it grows 300 centimetres in a decade. tree →

Note

Countable: a decade, decades. In maths: 1 decade = 10 years; 1 century = 100 years = 10 decades. «Decades» alone means «many years» (at least twenty). Do not confuse with «decayed» (rotted).

In Jewish tradition

In Sefer Yetzirah, the "decade" is the group of ten Sefirot, the ten basic numbers or powers through which God made the world.

Interpretation. Tradition reads the ten as the ten "infinitudes" or utterances that work with the 22 letters to form creation. Pythagoras's followers also thought ten was a holy number.

Examples

• The decade out of nothing has the following ten infinitudes: (Sefer Yetzirah, Kalisch 1877) tree →
• They consist of a decade out of nothing [5] and of twenty-two fundamental letters. (Sefer Yetzirah, Kalisch 1877) tree →
• The disciples of Pythagoras looked upon the decade as a holy number, and swore by it and by the Tetraktys which contain the number ten, (Sefer Yetzirah, Kalisch 1877) tree →

Note

Countable: a decade, decades. In maths: 1 decade = 10 years; 1 century = 100 years = 10 decades. «Decades» alone means «many years» (at least twenty). Do not confuse with «decayed» (rotted).