The Jargon File (version 4.4.7, 29 Dec 2003):

software bloat
 n.

    The results of second-system effect or creeping featuritis. Commonly
    cited examples include ls(1), X, BSD, and OS/2.


The Free On-line Dictionary of Computing (30 December 2018):

software bloat
bloat

    The result of adding new features to a program
   or system to the point where the benefit of the new features
   is outweighed by the extra resources consumed (RAM, disk
   space or performance) and complexity of use.  Software bloat
   is an instance of Parkinson's Law: resource requirements
   expand to consume the resources available.  Causes of software
   bloat include second-system effect and creeping
   featuritis.  Commonly cited examples include Unix's "ls(1)"
   command, the X Window System, BSD, Missed'em-five,
   OS/2 and any Microsoft product.

   [Jargon File]

   (1995-10-16)