Wiktionary
vb. (present participle of pass out English)
Wikipedia
Passing out is the completion of a course by military or other service personnel or the graduation from a college. Soldiers sometimes take part in a passing out parade upon completion of a basic training course.
The parade may also be referred to as a 'Marching out' parade as it is at the Army Recruit Training Centre at Kapooka in Australia.
Usage examples of "passing out".
It was, as he instantly recalled, the face of the young man he had seen, the day before, passing out of the Parker House, and had noted as not conforming to type, as not having an American hotel face.
It is still less satisfactory because it leads to the result that the light emitted by the stars and also individual stars of the stellar system are perpetually passing out into infinite space, never to return, and without ever again coming into interaction with other objects of nature.
Across the hall in front of me I saw Earl Dexter passing out of the Museum.
Already some of the weakest and most timid of their numbers might be seen passing out hastily into the gardens by the back gates, like engineers who had fired a train, and were escaping ere the explosion burst forth.
Lucretius liked to use words and forms which were passing out of use in the world around him.
It was wonderful to be once more re-entering the doors of Givre with him, and as the old house received them into its mellow silence she had again the sense of passing out of a dreadful dream into the reassurance of kindly and familiar things.