Definition from Wiktionary, the free dictionary
Compression of a l'arma! (“to the arms!”).
alarma f (plural alarmes)
- (military) alarm (a call to arms in preparation against an approaching enemy)
- (by extension)alarm (a warning of any type of danger)
- (psychology) alarm (fear or apprehension caused by a perceived danger)
Derived terms 
- Third-person singular present indicative form of alarmar.
- Second-person singular imperative form of alarmar.
Audio (Argentina) (file)
alarma f (plural alarmas)
alarma (infinitive alarmar)
- Third-person singular (él, ella, also used with usted?) present indicative form of alarmar.
- Informal second-person singular (tú) affirmative imperative form of alarmar.