“绿袖子”是什么？

《绿袖子》——斥欢斥爱，绿袖无常
　　我思断肠，伊人不臧。 Alas my love, you do me wrong

　　弃我远去，抑郁难当。 To cast me off discourteously

　　我心相属，日久月长。 I have loved you all so long

　　与卿相依，地老天荒。 Delighting in your company

　　绿袖招兮，我心欢朗。 Greensleeves was all my joy

　　绿袖飘兮，我心痴狂。 Greensleeves was my delight

　　绿袖摇兮，我心流光。 Greensleeves was my heart of gold

　　绿袖永兮，非我新娘。 And who but my Lady Greensleeves

　　我即相偎，柔荑纤香。 I have been ready at your hand

　　我自相许，舍身何妨。 To grant whatever you would crave

　　欲求永年，此生归偿。 I have both waged life and land

　　回首欢爱，四顾茫茫。 Your love and good will for to have

　　伊人隔尘，我亦无望。 Thou couldst desire no earthly thing

　　彼端箜篌，渐疏渐响。 But still thou hadst it readily

　　人既永绝，心自飘霜。 Thy music still to play and sing

　　斥欢斥爱，绿袖无常。 And yet thou wouldst not love me

　　绿袖去矣，付与流觞。 Greensleeves now farewell adieu

　　我燃心香，寄语上苍。 God I pray to p