The underlined expression doesn't mean anything. However:
The man in black - the man wearing black
bowed - bent over at the waist
once - one time
to the crowd - in the direction of the crowd
and disappeared - he left
As RonBee's reply shows, "black" has nothing to do with "bowed" in this context; and the "bowed" has the diphthong /aʊ/ (as in "how"). Another context would allow another meaning - "wearing a black bow": "He followed the little black-bowed girl." Here, the diphthong is /ǝʊ/ (as in "oh").
black bowed 
Re: black bowed 
As RonBee's reply shows, "black" has nothing to do with "bowed" in this context; and the "bowed" has the diphthong /aʊ/ (as in "how"). Another context would allow another meaning - "wearing a black bow": "He followed the little black-bowed girl." Here, the diphthong is /ǝʊ/ (as in "oh").
Linear Mode
