used as a function word to indicate an alternative. the equivalent or substitutive character of two words or phrases. or approximation or uncertainty. EITHER. WHETHER. used in logic as a sentential connective that forms a complex sentence which is true when at least one of its constituent sentences is true. BEFORE. the heraldic color gold or yellow. a logical operator that requires at least one of two inputs to be present or conditions to be met for an output to be made or a statement to be executed. operating room. operational research; operations research. Oregon. owner's risk. own recognizance. one that does a (specified) thing. condition: activity.