The Collaborative International Dictionary of English v.0.48:

Macrobiotic \Mac`ro*bi*ot"ic\, a. [Gr. ? long-lived; makro`s
   long + bi`os life: cf. F. macrobiotique.]
   1. Long-lived. -- Dunglison.
      [1913 Webster]

   2. Of or pertaining to macrobiotics.
      [PJC]

   3. Of or pertaining to macrobiotic food; serving macrobiotic
      food.
      [PJC]

WordNet (r) 3.0 (2006):

macrobiotic
    adj 1: of or relating to the theory or practice of macrobiotics;
           "macrobiotic diet"

Moby Thesaurus II by Grady Ward, 1.0:

40 Moby Thesaurus words for "macrobiotic":
   abiding, age-long, aged, ancient, antique, chronic, constant,
   continuing, diuturnal, durable, enduring, evergreen, hardy,
   immutable, intransient, inveterate, lasting, long-lasting,
   long-lived, long-standing, long-term, longeval, longevous,
   of long duration, of long standing, perdurable, perduring,
   perennial, permanent, perpetual, persistent, persisting, remaining,
   sempervirent, stable, staying, steadfast, tough, unfading, vital