Glossary

Apex: The point at which a car is closest to the inside of a corner; the geometry of the apex determines corner entry and exit speed.
Bargeboard: Vertical flow-conditioning surfaces between the front wheels and sidepods, largely legislated away for 2022.
Blistering: Tyre surface failure caused by overheating from the inside out.
Blue flag: Shown to a driver about to be lapped, requiring them to let the faster car past.
Box: Radio instruction to pit, from the German 'Boxenstopp'; used because it is easier to hear than 'pit'.
Brake bias: The front-to-rear distribution of braking force, adjustable from the cockpit.
Chicane: A tight sequence of corners inserted to slow cars, usually retrofitted for safety.
Clean air: Undisturbed airflow; a car in clean air produces full downforce, one following closely does not.
Concorde Agreement: The commercial and governance contract between the FIA, the commercial rights holder and the teams. First signed 1981.
Cost cap: The annual spending limit on team operations, introduced in 2021 and excluding driver salaries, marketing and the three highest-paid staff.
DNF: Did Not Finish.
DRS: Drag Reduction System, 2011-2025: a driver-adjustable rear wing flap usable within one second of the car ahead in designated zones.
Degradation: The loss of tyre performance over a stint, distinct from wear; Pirelli's tyres are specified to degrade deliberately.
Delta time: A target lap time drivers must not beat, used to enforce Virtual Safety Car conditions.
Dirty air: The turbulent wake behind a car, which reduces the downforce of a car following closely.
Downforce: Aerodynamically generated load pressing the car onto the track, increasing grip at the cost of drag.
ERS: Energy Recovery System: the electrical part of the power unit.
Flat spot: A locally worn patch on a tyre caused by locking a wheel under braking; produces vibration severe enough to force a pit stop.
Formation lap: The lap from the grid to the grid before the start, used to warm tyres and brakes.
Ground effect: Downforce generated by accelerating airflow under the car through Venturi tunnels. Used 1977-1982 and again from 2022.
HANS: Head and Neck Support device, mandatory since 2003, tethering the helmet to the shoulders to prevent basilar skull fracture.
Halo: The titanium cockpit protection structure mandated in 2018, able to withstand around 12 tonnes.
Homologation: FIA certification that a car, part or circuit meets the regulations.
Lift and coast: Lifting off the throttle before the braking point to save fuel, energy or brake temperature.
MGU-H: Motor Generator Unit - Heat, recovering energy from exhaust gases via the turbocharger. Used 2014-2025 and removed for 2026.
MGU-K: Motor Generator Unit - Kinetic, recovering energy under braking and deploying it as drive.
Marbles: Discarded rubber off the racing line; drivers avoid it because it destroys grip.
Overcut: Staying out longer than a rival, using clear air to build a gap before stopping.
Overtake Mode: The 2026 replacement for DRS: additional energy deployment for a car within one second at the detection point.
Parc ferme: The state, from the start of qualifying, in which set-up changes are prohibited without a pit-lane start.
Pit window: The lap range in which a stop makes strategic sense.
Plank: The wooden (Jabroc) skid block under the floor, introduced in 1994 to enforce a minimum ride height. Excessive wear means disqualification.
Pole position: First place on the starting grid, awarded on qualifying time.
Porpoising: Violent vertical oscillation caused by ground-effect stall and recovery; the defining problem of the 2022 season.
Power unit: The full hybrid assembly since 2014: internal combustion engine, turbocharger, MGU-K, energy store and control electronics (plus MGU-H until 2026).
Slipstream: The low-drag region behind a car, used to gain speed before an overtake.
Sprint: A short Saturday race introduced in 2021, currently run at six events, with its own qualifying session since 2024.
Stewards: The panel of four officials, including one former driver, who rule on incidents and apply penalties at each event.
Superlicence: The FIA licence required to race in F1, earned through a points system across junior categories. Introduced in its current form in 2016.
Tow: The British term for slipstream.
Track limits: The white lines defining the circuit; a lap is deleted if all four wheels go beyond them.
Undercut: Pitting before a rival and using fresh-tyre pace to emerge ahead when they stop.
Virtual Safety Car: A field-wide delta-time speed restriction introduced in 2015, allowing yellow-flag conditions without bunching the field.
Wind tunnel restriction: Aerodynamic testing time allocated in inverse proportion to championship position, to compress the competitive order.