Alright kiddies, there are two definitions for this.

1) In baseball, this refers to the superstition that a rookie's second year will be a bad one, i.e. he gets injured, plays a horrible season, or the team falls apart on account of his playing style.

2) In college, it refers to the time when classes are getting much harder, sometimes even the harder than the following years in an undergraduate program. It can also refer to the student changing his/her major and having a hard time with it at first.
1) There are too many to list, check the stats at www.mlb.com

2) Little Billy suffered the Sophomore Jinx when he broke down working on a Rigid Body Mechanics assignment. He's now an Anthropology major.
by Matt August 18, 2005
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