A structure or substance not normally present but produced by an external agent or action, such as a structure seen in a microscopic specimen after fixation that is not present in the living tissue.

• 矫作物非正常出现而是由外界因素或作用所产生的一种结构或物质，如经固定后，在显微镜下才能看到的标本中的一种活生命组织中不会出现的结构