arm
AHRM
/ɑːrm/
To prepare or engage a safety or emergency mechanism (such as an aircraft door emergency slide) for automatic operation.
Means locking emergency deployment pins into place so slides inflate automatically if opened in emergency.
The story behind the word. Traced to Latin 'arma' (tools or weapons of warfare). Over time, military engineering expanded the meaning from wielding weapons to setting active mechanical triggers. Aviation standardized the term for setting emergency slides before taxiing.
Word relationships
- activate: 'Activate' means turning a system fully on, while 'arm' means setting a system to trigger automatically upon impact or opening.
- prime: 'Prime' implies preparing something for firing or starting, whereas 'arm' emphasizes safety release readiness.
- disarm: Disarm means setting safety mechanisms to neutral so emergency devices will not deploy upon opening doors.
Commonly confused with
- Disarm: 'Arm' prepares the emergency slide to deploy; 'disarm' deactivates it so passengers can exit normally at the gate.
Word family
- armed (adjective): Equipped or set to deploy emergency equipment automatically.
- disarm (verb): To deactivate an emergency slide or weapon mechanism.
Collocations
- arm doors
- arm slides
- arm system
- arm and cross-check
Example sentences
- "Cabin crew, please arm doors and cross-check before we push back from the gate." Departure Call
- "The crew worked quickly to arm the defense systems before entering the hostile channel." Naval Tactics
Memory hook
ARM the door to put its emergency ARMOR and slide ready for action. ARM = Ready emergency mechanism for auto-release.
When not to use
Do not confuse with carrying physical weapons in non-technical contexts.
Fun facts
- If a flight attendant opens an aircraft door that is still 'armed', an emergency slide will forcefully inflate in under 6 seconds, blowing out the door!
Related words
Also appears in
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