Sentence:  Squatting on our haunches beside the flat stone we broke them on , we <WSD>were</WSD> safe behind the high closed gates at the end of the drive : safe from interruption and the observation and possible amusement of the passers-by . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)