The Collaborative International Dictionary of English v.0.48:

lights \lights\ (l[imac]ts), n. pl. [So called from their
   lightness.]
   The lungs of an animal or bird; -- sometimes coarsely applied
   to the lungs of a human being.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

64 Moby Thesaurus words for "lights":
   arc, arc light, assumption, attitude, bellows, climate of opinion,
   color filter, common belief, community sentiment, conceit, concept,
   conception, conclusion, consensus gentium, consideration, ctenidia,
   dimmer, estimate, estimation, ethos, eye, feeling, floats, flood,
   floodlight, footlights, foots, gelatin, general belief, gills,
   idea, impression, judgment, klieg light, light plot, limelight,
   lungs, marquee, medium, mind, mystique, notion, observation,
   opinion, personal judgment, point of view, popular belief,
   position, posture, presumption, prevailing belief, public belief,
   public opinion, reaction, sentiment, sight, spot, spotlight,
   stance, theory, thinking, thought, view, way of thinking