Okino: An uneven bar dismount named after Betty Okino, who first performed the skill in international competition. It consists of a free hip underswing with ½  twist to layout back salto. The skill has been rated by the FIG as a D level skill and the FIG number is 8.402.

Okino: An balance beam skill named after Betty Okino, which she first performed in the  1991 World Championships. It is a triple pirouette (triple turn). The skill has been rated by the FIG as a E level skill and the FIG number is 3.501.

Olympic Order: This refers to the order in which gymnastics events proceed in international competition.  Unless there are other valid meet planning reasons not to do so, it is the order at every other gymnastics competition, also.  The Olympic order for women is vault, uneven bars, balance beam and floor exercise. The Olympic order for men’s competition is floor exercise, pommel horse, still rings, vault, parallel bars and horizontal bar. Olympic order for rhythmic gymnasts is rope, hoop, ball, clubs and ribbon. 

Omelianchik: A balance beam skill named after Romanian gymnast Oksana Omelianchik.  It is a back dive with ¼ (or ¾) twist to land in a handstand.

O'Neill: An still rings skill named after U.S. gymnast Paul O-Neill.  It consists ofa stretched double feige backward to a hang.  The skill has been rated by the FIG as a E level skill.

Optionals: A category of competition in which gymnasts and coaches individually create routines in which the gymnast may perform skills of their choosing which meet the rules as specified in the FIG code of points and under the constraints of listed special requirements. Optional gymnasts present their best skills in their routines.  Optional gymnasts are higher level gymnasts than Compulsory gymnasts are. 

Overgrip: An overgrip is hanging (swinging) on the bar with the palm of the hand and fingers facing away from the gymnast.

Overshoot: A release move from the high bar to the low bar.  It starts on the on high bar facing low bar.  The gymnast swings up and over the low bar with a half turn to a catch of the low bar.  Also called an Underswing.
 
 

Gymnastics Dictionary