A sportscast is a sports programme on television or radio — a game being shown, or a show about games. If you are watching a baseball match on TV with someone talking over it, that is a sportscast. This is American English. British speakers would say 'sports broadcast', 'the coverage', or just name it: 'the match was on TV'. So it is a useful word to recognise, especially in American news writing, but not one your students need to reach for themselves. Notice the family around it. The person doing the talking is a 'sportscaster' — the commentator, the person describing the play or reading the results. That word is much more common than 'sportscast' itself, and it is the one you are more likely to meet. There is also a verb, 'to sportscast', but it is rare and sounds a little odd; people say 'call the game' or 'cover the game' instead. The word covers both the live game with commentary and the studio segment where someone runs through the day's scores — American local news bulletins have a weathercast and a sportscast, each a fixed slot in the programme. That newsroom use is where the word feels most at home.

體育（賽事）轉播、體育新聞時段。這是美式用法；台灣一般就說「（球賽）轉播」「體育新聞」，播報的人叫「體育主播」，也就是英文的 sportscaster。