Metaphor

Saying one thing through another, without a word of comparison: instead of saying that something is like something else, one says that it is. The image transfers to the subject the qualities of the thing it is identified with.

In Madame Bovary

her life was cold as an attic whose skylight faces north, and boredom, a silent spider, spun its web in the shadow at every corner of her heart

Boredom becomes a "silent spider" that spins "its web" in every corner of the heart. The image, without a word of comparison, shows a feeling that grows slowly and silently, filling everything until it traps Emma from within.

Part I, Chapter 7, the narrator

like sailors in distress [...] she cast desperate eyes over the solitude of her life, searching far off for some white sail in the mists of the horizon

Part I, Chapter 9, the narrator

love, as she believed, had to arise suddenly, with great tumult and flashes [...] a storm from the heavens that falls on life and churns it up, tears wills away like leaves and carries the whole heart off into the abyss.

Part II, Chapter 4, the narrator

What an abundance of illusions! Now she had none left! She had spent them all on the adventures of her soul, in every successive condition, in virginity, in marriage and in love, losing them continually throughout her life, like a traveler who leaves part of his wealth at every inn along the way.

Part II, Chapter 10, the narrator

because a request for money is the coldest and most devastating of all the storms that can break upon love.

Part III, Chapter 8, the narrator