continue, recommend

紹 is composed of 糸(the picture of a coil) and 召, the original form of 召 is the picture of two hands holding a spoon and taking up wine from a wine bottle to a bowl, depicts master(most likely an emperor) serving his guest(most likely the feudal barons) in ancient China, in order to maintain good relation, while 糸 means linking, so 紹 has the meaning of continuation or recommending someone.