subs. (American).—1.  One who BOOMS or causes an enterprise to become flourishing, active or notorious.

1

  1883.  Times, 26 Sept., 8. [He] is a North-Western ‘BOOMER’ of great earnestness.

2

  1885.  Boston (Mass.) Journal, Aug. 19, 2. 4. The Oklahoma BOOMERS.

3

  2.  (common).—Anybody (or anything) considerably above the average: a fine woman, a horse with extra good points, etc., etc.

4