[误] My wife is fond of asking her friends to stay for a casual meal.

　　[正] My wife is fond of asking her friends to stay for a light meal.

　　注：casual 可作“不拘礼节的，非正式的”讲，如：clothes for casual wear(便服)。但“便饭”人们习惯用形容词 light，该词也有“随便的，不重要的”之意，如：a light conversation(闲谈)。