obscuridad, f., darkness, obscurity.
obscur-o, -a, obscure, dark, confused.
obsequiar, to pay attention to, treat.
observación, f., observation.
observar, to observe.
obstáculo, m., obstacle.
obtener, to obtain.
obtengamos, pres. subj. of obtener.
ocasión, f., occasion, opportunity.
ocio, m., leisure.