rabbithole

Noun

rabbit hole (plural rabbit holes)

1. (figuratively, usually) A bizarre world, where everyday rules do not apply.
2. (figuratively, usually) A way into such a world.
   • These mushrooms will take you down the rabbit hole, man.

   Synonyms:

   looking-glass

3. (broadly, figuratively) A time-consuming tangent or detour, often one from which it is difficult to extricate oneself.
   • Near-synonym: rabbit trail (regiolectic)

   Synonyms:

   wild-goose chase, rabbit trail[regiolect]]ic>

4. (figuratively) The initial clue that leads to an alternate reality game.

   Synonyms:

   trailhead

5. Used other than figuratively or idiomatically: see rabbit, hole. The entrance to a rabbit warren or burrow; the whole warren or burrow.
   • The rabbit-hole went straight on like a tunnel for some way, and then dipped suddenly down, so suddenly that Alice had not a moment to think about stopping herself before she found herself falling down what seemed to be a very deep well.1866, Lewis Carroll, chapter 1, in Alice's Adventures in Wonderland