An extended metaphor is a metaphor that continues into the following sentences. An extended metaphor is also a metaphor developed at great length, occurring frequently in or throughout a work.

For example, if one starts with the metaphor of The seeds of discontent have already been sown, an extension could be It remains to see whether weed or flower will spring forth.

Another example of an extended metaphor would be, The winds were ocean waves, thrashing against the trees limbs. The extension would then be, The gales remained thereafter, only ceasing when the sun went down. Their waves clashed brilliantly with the water beneath, bringing foam and dying leaves to the shore.