She grew up 'in the shadow of' her very popular sister. [=people did not notice her because of all the attention that was given to her sister]
He couldn't escape his father's 'shadow'. [=he couldn't escape the influence of his powerful/successful father]
a town located in the 'shadow' of the Rocky Mountains [=a town located very close to the Rocky Mountains]
(..) He cannot yet take physical form... ...but his spirit has lost none of its potency. Concealed within his fortress,the Lord of Mordor sees all. His gaze pierces cloud,shadow,earth and flesh. You know of what I speak,Gandalf. A Great Eye,lidless,wreathed in flame. The Eye of Sauron. (..)2001 The Lord of the Rings: The Fellowship of the Ring
(..) My precious. For years it poisoned his mind. And in the gloom of Gollum's cave,it waited. Darkness crept back into the forests of the world. Rumor grew of a shadow in the East... ... whispers of a nameless fear. And the Ring of Power perceived... ...its time had now come. It abandoned Gollum. (..)2001 The Lord of the Rings: The Fellowship of the Ring