Sentence:  Over the rapidly diminishing outline of a jump seat piled high with luggage Herry 's black brushcut was just discernible , near , or enviably near that spot where - hidden - more delicately textured , most beautifully tinted hair must still be streaming <WSD>back</WSD> in cool , oh cool wind sweetly perfumed with sagebrush and yucca flowers and engine fumes . 
Meaning of the word marked with <WSD> tags:  at or to or toward the back or rear