Definition
The airspeed shown directly on the cockpit airspeed indicator, derived from the difference between ram air pressure (from the pitot tube) and static air pressure, before any corrections for instrument error, position error, air density, or compressibility are applied.
Plain English
The speed your airspeed indicator is showing you right now. It is the raw reading on the dial, with no adjustments made.
Context Anchor
Seen on the airspeed indicator and in procedures, checklists, aircraft limits, climb speeds, and approach speeds.
Derivation
"Indicated" comes from the Latin indicare, meaning "to point out" or "to show." In this case, it literally means the speed the instrument is pointing to — what the dial is showing — as opposed to a corrected or calculated speed.
Why Pilots Care
All aircraft performance speeds such as rotation, climb, and approach are published and flown using indicated airspeed.
Intuition Check
IAS does not mean true speed through the air, and it does not mean speed over the ground. It means the airspeed indicated by the cockpit instrument.
Example Sentence 1
Rotate at an indicated airspeed of 55 knots and climb out at 75.
Example Sentence 2
The approach checklist called for reducing to an IAS of 80 knots on final.