There are only 2 words that can be made using all of the letters: R, N, E, U, S, I, C, A, and N. They are "insurance" and "nuisancer".
However, 324 words of 3 letters or more can be made from these 9 letters if all of the letters don't have to be used in each word. Some of the longer, more complex, and/or frequently used ones are: aneurins, crannies, ennui, anise, scanner, insane, insure, insnare, sunnier, sinner, saucer, siren, earn, nun, cruise, ace, arc, canine, cause, acne, and acre.
And yes, the word "nuisancer" is indeed defined as "one who makes or causes a nuisance."
Play a little word scramble below: