operation code 
noun Computing
The part of a machine code instruction that defines the operation to be performed.Send both numbers and the operation code to the execution unit.
- Eastertide
- Easter time
- Easter week
- Easter weekend
- east-facing
- East Flanders
- East Friesian
- East Frisian
- East German
- East Germanic
- east half
- East Hampton
- East Harlem
- East Hartford
- East India
- East India Company
- East India Docks
- East India House
- East Indiaman
- East Indian
- East Indian cedar
- East Indian jalap
- East Indian Plum
- East India pale ale
- East Indie