Orthogonal
/ɔːrˈθɒɡənəl/adjective
Meeting at right angles, or more generally independent, so that varying one thing has no effect on the other.
The Greek roots
Literally: “right-angled”
The story of the word
Euclid's phrase for a right angle was ὀρθὴ γωνία, an upright angle, the angle a plumb line makes with level ground, which is why ὀρθός carries both 'straight' and 'correct' and turns up in orthodox and orthodontics. Mathematics generalised the geometry until two functions with no overlap could be called orthogonal, and engineers then borrowed that abstraction for design decisions that do not interfere. The vogue sense of 'irrelevant to the question' is a further stretch, and pedants resist it.
- How it travelled
- Ancient Greek → Latin → French → English
- First recorded
- 16th century
The same roots elsewhere
Other languages reached for exactly the same Greek pieces.
Same family
In a sentence
Cost and latency turned out to be orthogonal, so we could tune them separately.