Sentence:  It is at precisely such moments that he encounters a couple of undergraduates , faces alight , holding hands and talking happily as they come along , oblivious of him , or <WSD>throwing</WSD> him the most fleeting and casual of glances , such as they would give a tethered goat . 
Meaning of the word marked with <WSD> tags:  convey or communicate; of a smile, a look, a physical gesture