pi
nounUK /paɪ/
US /paɪ/
Pi is a special number that tells how far around a circle is compared to across it.
We used pi to find the distance around the round table.
SYNONYMS
RELATED WORDS
OTHER MEANINGS
2. The sixteenth letter of the Greek alphabet.
The symbol pi looks like a small table with two legs.
3. A jumbled mix of printed letters, often from spilled type.
The old printing press left the page in pi.
4. A common short name for a mathematical constant used in trigonometry.
Sine and cosine are often taught together with pi.