RSA, the /ˌɑːr es ˈeɪ/ abbreviation for
the Royal Society of Arts; a British organization that encourages education in arts (=not science) subjects and for business. Its full name is the Royal Society for the Encouragement of Arts, Manufactures & Commerce.

[TahlilGaran] Dictionary of Contemporary English ▲

RSA
Republic of South Africa 
Rivest, Shamir, & Adleman (public key encryption technology)

[TahlilGaran] Acronyms and Abbreviations Dictionary ▲