Definition of or :
1. A particle that marks an alternative; as, you may read or may write, -- that is, you may do one of the things at your pleasure, but not both. It corresponds to either. You may ride either to London or to Windsor. It often connects a series of words or propositions, presenting a choice of either; as, he may study law, or medicine, or divinity, or he may enter into trade.
2. Ere; before; sooner than.
3. Yellow or gold color, - represented in drawing or engraving by small dots.
surgery, roughly, instead of, neither, about, operating room, operation, nor, operating theater, surgical operation, instead, surgical process, operating theatre, surgical procedure, rather, approximately, practically, beaver state, oppositely, either, Oregon