ondulante, rolling.
ondular, to undulate.
operación, f., operation, act.
oponerse, to oppose.
oprimir, to oppress, press, clasp.
opuesto, -a, opposite.
opulento, -a, rich, opulent.
ora, now; — ... —, now ... now (or again).
oración, f., prayer, orison, adoration; á la —, to prayers.
orden, m., order, regularity, decorum; f., order, command, insignia.