the [universlty] [student] had not done enough [revision] and made a real  cockup of his [finals] which meant he would have to resit them later in the year
a cockup means [someone] has made a real [mess] of [something]
"the [universlty] [student] had not done enough [revision] and made a real  cockup of his [finals] which meant he would have to resit them later in the year" What is the definition of "cockup"?