"an obscure turn of phrase" "an impulse to go off and fight certain obscure battles of his own spirit" "their descriptions of human behavior become vague, dull, and unclear" "vague...forms of speech...have so long passed for mysteries of science"
"an undefined term" "undefined authority" "some undefined sense of excitement" "vague feelings of sadness" "a vague uneasiness"
"a dim figure in the distance" "only a faint recollection" "shadowy figures in the gloom" "saw a vague outline of a building through the fog" "a few wispy memories of childhood"
