This word was created from a tico
slang called Malespín. The costarican
army, in the middle of the war with Nicaragua, found that the military orders were intercepted by the "nica" spies. The general Malespín proposed that the letter A was changed by E, the I by O, M to P and T to B.
So Tuanis is the code word from "Buenos" (good, great) in Malespín.
Also "Malos" (bad, evil) is Pelis or Work ("Trabajo") is "Brete" ("Breteji", actually. We
drop the last
two letters with the time).