WordNet (r) 3.0 (2006):

weeds
    n 1: a black garment (dress) worn by a widow as a sign of
         mourning [syn: weeds, widow's weeds]

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

weeds
 n.

    1. Refers to development projects or algorithms that have no possible
    relevance or practical application. Comes from ?off in the weeds?. Used in
    phrases like ?lexical analysis for microcode is serious weeds....?

    2. At CDC/ETA before its demise, the phrase go off in the weeds was
    equivalent mainstream hackerdom's jump off into never-never land.


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

weeds

   1. Refers to development projects or algorithms that have no
   possible relevance or practical application.  Comes from "off
   in the weeds".  Used in phrases like "lexical analysis for
   microcode is serious weeds."

   2. At CDC/ETA before its demise, the phrase "go off in the
   weeds" was equivalent to IBM's branch to Fishkill and
   mainstream hackerdom's jump off into never-never land.

   [Jargon File]