RhymeZone: voa definitions

Definitions of VOA:

noun: (US, radio) Initialism of Voice of America.
noun: (mathematics) Initialism of vertex operator algebra
noun: Initialism of visa-on-arrival. [A simplified method of issuing visa (a permit to enter and leave a country) on arrival, as an alternative to a complete visa-free entry.]
noun: (UK) Initialism of Valuation Office Agency.

(Definitions from Wiktionary)