• Ostinato (from Italian: stubborn) - Music and Dance Term. A motif or phrase that persistently repeats in the same musical voice, frequently in the same pitch. Well-known ostinato-based pieces include both classical compositions such as Ravel's Boléro and popular songs such as Donna Summer’s "I Feel Love" (1977) and Henry Mancini's theme from Peter Gunn (1959). See Beat, Compás, Improvisational, Lead, Legato, Musicality, Ostinato, Phrase, Ritmo, Rubato, Staccato and Syncopation.

• Ochito Con Traspié (Small Eight with Stumble) - A variation of Ocho Atrás in Silver Tango.

• Ocho (Eight, Figure eights/ Eight from your front body) - Key Pattern 4 in Bronze Tango and Key Pattern 4 in Bronze Milonga. Executed as a walking step with flexed knees and feet together while pivoting, ochos may be danced either forward or backward and are so designated from the woman’s perspective. El Ocho is considered to be one of the oldest steps in tango along with Caminada, the walking steps. It dates from the era when women wore floor length skirts with full petticoats and danced on dirt floors. Since the woman’s footwork could not be directly observed the quality of her dancing was judged by the figure she left behind in the dirt after she danced away. For Ocho technique, the woman closes to the man on each pivot, and then moves into promenade if the lead continues. The ocho is not a single sweeping pivot move. Woman always thinks Molinete. Not Ocho.

• Ocho Atrás (Back Eight/ Eight from your back body) - Key Pattern 3 in Silver Tango. Ocho to the back: Back ochos for the woman (i.e., crossing behind).

• Ocho Círculo – Bronze Milonga from El Ocho.

• Ocho Cortado (Cutting Eight) - Key Pattern 3 in Bronze Pecho and a variation of Ocho Quebrado in Bronze Vals. Ocho Cortado occurs when a Molinete or an Ocho-like movement is stopped and sent back upon itself. Typical in club-style tango where many such brakes are used to avoid collisions. Describes a movement done on either foot, pivoting forward and backward, and going either left or right. Also sometimes called the Milonguero Cross. The cutting part is really the forward side step of the Molinenes.

• Ocho Cruzado (Crossed Eight) - Key Pattern 2 in Gold Milonga.

• Ocho Defrente (Ocho to the Front) - Forward ochos for the woman (i.e., crossing in front).

• Ocho Dividido (Divided Eight) - A variation of Entrecortado in Gold Vals.

• Ocho Fintado (Feinted Eight) - A variation of Entrecortado in Gold Vals.

• Ocho Quebrado (Breaking Eight) - Key Pattern 4 in Bronze Vals and a variation of Ocho in Bronze Tango.

• Ondas (Waves) - A variation of Vueltecita in Silver Milonga.

• Orillero (Outskirts; suburbs).

• Orquesta (Orchestra) - A large tango band like those of the "Golden Age" of tango frequently referred to as "Orquesta Tipica" , such as an 11-piece tango ensemble. See Milonga, Confitería Bailable, Bailongo, Bailar, Ronda, Práctica, Piso, Pista, Bandoneón, Parejas, Abrazo, Pinta, Postura, Bien Parado, Códigos, Cortina, Bailamos, Tanda, and Cabeceó.

• Oscilación (Oscillation) - A variation of Péndulo in Bronze Milonga.

• Otra Vez (Another Time; Repeat; Do Again) - See Caminada, Caminar, Contra Body Movement, Contra Body Movement Position, Corridata, Cross System, Elevadas,Entregarme, Giro, Junta, Lento, Liso, Marcar, Mira, Parallel System, Paso, Pisar, Puente, Seguirv and Suave.
​