WordNet sense 1 (lacking clarity or distinctness):

dim, faint, vague, wispy

WordNet sense 2 (not clearly defined or easy to perceive or understand):

indistinct

WordNet sense 3 (lacking in substance):

wraithlike

WordNet sense 4 (lacking material form or substance; unreal):

insubstantial, unreal, unsubstantial

WordNet sense 5 (filled with shade):

shady, umbrageous, shadowed

WordNet sense 6 (protected from heat and light with shade or shadow):

shaded