pipe-opener

plural pipe-openers

1. A device for putting a hole in a pipe.
2. A device or mechanism for clearing obstructions in a pipe.
3. hobbiesA practice event; a warm-up.

   They will note the doings of the favourite for some particular race, scanning him keenly and critically ; they will see how he takes his pipe-opener, or if he breaks down, or if he turns lame, or is absent from exercise.

   1873, The Contemporary Review, volume 22

   1 more example

   I would rather have the horse fit by the week-end preceding the three-day event and then, apart from a good sharp two-furlong pipe-opener after the dressage test before cross-country day, only do slow but interesting work, if necessary for long periods if the horse has an excitable temperament.

   1976, Caroline Silver, Lucinda Prior-Palmer, Eventing: the book of the three-day event

4. figurativelyA brisk walk or other aerobic exercise; a constitutional.
5. figurativelyAn example that serves as an introduction.

   That tale may have served as a pipe-opener, but one could not see its wood for its trees, so I threw it away.

   1991, Rudyard Kipling, edited by Thomas Pinney, Something of myself and other autobiographical writings

   1 more example

   There is just no way to experience these pieces by looking from the outside, or in photos or on video: the initial view of them from the balcony above the Arcelor gallery is impressively dramatic, yet it's the merest pipe-opener to what unfolds close up and at floor level.

   2005, Robert Hughes, “Man of Steel”, in Robert Dessaix, editor, The Best Australian Essays 2005