Definitional blurring

Definitional blurring is the fallacious practice of subtly changing the definitions used in an original argument in order to attack what really constitutes a different position, i.e. attacking a strawman.

An example of definitional blurring occurs in the argument Biological sex is not binary, where the definition of sex is switched to a host of inner biological mechanisms such as chromosomes, hormones, human feelings and the likes, instead of the steelman definition, which is the production of viable gametes as part of a reproductive act.