Definition
A graduated metal rod inserted into an engine's oil sump (or other fluid reservoir) used to measure the quantity of fluid present. The rod is withdrawn after insertion, and the fluid level is read against marked indicators on the rod, typically showing minimum and maximum acceptable levels.
Plain English
A marked stick you pull out of the engine to check how much oil is inside. The wet line on the stick tells you the level.
Context Anchor
Seen during preflight inspections, engine servicing, and maintenance checks when confirming oil or other fluid quantity.
Derivation
From 'dip' (to lower briefly into a liquid) plus 'stick.' The name describes exactly what it does — a stick you dip into the fluid to check the level.
Why Pilots Care
Confirms adequate oil supply for engine lubrication; running low risks overheating or seizure.
Intuition Check
Do not think of a dipstick as just any stick or handle. In aircraft maintenance, it is a marked measuring tool used to show a fluid level.
Example Sentence 1
During preflight, the pilot pulled the dipstick, wiped it clean, reinserted it fully, and then checked the oil level against the markings.
Example Sentence 2
During the preflight walk-around the student pilot checked the dipstick on each engine to verify oil quantity.