The Collaborative International Dictionary of English v.0.48:

energy-releasing \energy-releasing\ adj.
   1. releasing energy. [Narrower terms: exothermic (vs.
      endothermic), exothermal]

   Syn: exoergic.
        [WordNet 1.5]

   2. catabolic. [prenominal] constructive-metabolic

   Syn: destructive-metabolic(prenominal).
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

energy-releasing
    adj 1: (of a nuclear reaction) occurring with evolution or
           releasing of energy [syn: exoergic, energy-releasing]
           [ant: endoergic, energy-absorbing]
    2: of or relating to catabolism [syn: destructive-metabolic,
       energy-releasing(a)]