precover

/P R IY0 K AH1 V ER0/
noun
  1. 1

    Something that occurs in preparation for a covering.

  2. 2

    (mathematics) A generalization of a cover in which the kernel may contain a non-zero pure subgroup.

verb
  1. 1

    (astronomy) To find an older image of an object in archived images after it has been discovered.