It is a tranquil moment, and my afternoon panic attack seems like ancient history.
Her face was tranquil, her hands, palms facing outward, lodged between her neck and rope, almost as if attempting to pull it away.
Milena Baroni, friends with Eliza for a year and a half, describes a "tranquil, calm" person.
1966. ALGOL-like language with sets and other extensions, for the Illiac IV. "TRANQUIL: A Language for an Array Processing Computer", N.E. Abel et al, Proc SJCC 34 (1969).