(n) overloading
(n) (comp) overlay routing
(n) opening number
(n) (comp) open-end wrench
(n) open caption
(n) (comp) OpenClient
(n) open sandwich
(n) open system hospital
(n) (comp) open source vendor
open source company
(n) (comp) open source code
(n) open display
(n) (comp) open network
(n) type of scuba fin with an open heel, also called "adjustable fins"
(n) (comp) open file description
(n) open planning
(n) open-reel tape
(n) open tournament
(n) all English (method of teaching English)
(exp) all-or-nothing
(n) all guarantee
(n) all-season coat
(n) all-season dress
(n) old-fashioned
(n) oil painting
(n) northern flying squirrel (Glaucomys sabrinus)
(n) (comp) office computer
(n) offshore company
(n) (comp) off-screen memory
(n) (comp) offline storage
(n) (comp) optical printer