Plain English Meaning
A span where the top number is ten times the bottom number. So 10 to 100 is one decade, 100 to 1,000 is another decade, and so on.
Full Definition
A range of values in which the upper limit is ten times the lower limit. In electronics and avionics, frequency response and instrument scales are often described per decade — for example, a filter that rolls off so many decibels per decade of frequency, or a tuning range from 100 Hz to 1,000 Hz spanning one decade.
Context Anchor
Seen in aircraft electrical, radio, and instrument-maintenance discussions when numbers are grouped by ten-times steps.
Derivation
From the Greek 'deka,' meaning ten. In everyday English a decade usually means ten years, but in technical work it simply means a factor of ten — any tenfold step, not specifically time.
Why Pilots Care
If a manual says a value changes by a decade, it means the value changes by a factor of ten, which is much larger than a small adjustment.
Analogy
Moving from 10 to 100 is one decade, like moving one major step up on a scale where each big step multiplies by ten.
Intuition Check
Do not assume decade means ten years here. In technical aviation use, it usually means a ten-times range or a group based on ten.
Example Sentence 1
The audio filter in the intercom attenuates noise by 20 decibels per decade above the cutoff frequency.
Example Sentence 2
Records showed that certain inspections were required once each decade.