tranquillus

Etymology
Probably from an earlier (with quantitative metathesis), from  + the root of.

Adjective

 * 1)  quiet, calm, still, tranquil
 * 2)  placid, composed, untroubled, undisturbed
 * 1)  placid, composed, untroubled, undisturbed
 * 1)  placid, composed, untroubled, undisturbed