senior /sēˈnyər or sēˈni-ər/

1. Elder
2. Older or higher in standing
3. More advanced
4. First

1. A person who is senior
2. A pupil in the senior part of a school
3. A fourth-year student at college (US)

seniority /sē-ni-orˈi-ti/ noun

1. The state or fact of being senior
2. Priority by age, time of service, or standing
3. A body of seniors or senior fellows

senior citizen noun

An old-age pensioner

senior common room or (Cambridge University) senior combination room noun

In some universities, a common room for the use of staff (cf junior common room, middle common room; abbrev SCR)

senior moment noun (informal)

A momentary lapse in memory, esp experienced by an older person

senior optime see optime

• original equipment manufacturer
• original equipment manufacturers
• originalities
• originality
• originally
• originals
• original sin
• originate
• originated
• originates
• originating
• originating application
• originating summons
• origination
• originations
• originative
• originator
• originators
• origins
• orillion
• orillions
• Orimulsion
• O-ring
• oriole
• orioles