What is an implied metaphor?

An implied metaphor is a type of metaphor which compares two things that are not alike and it does so without mentioning the name of one of them. Instead of mentioning the name of the second object, implied metaphor instead implies the comparison by using words or phrases, which describes the unmentioned object.

An example of implied metaphor is this: Ruth is drowning in love.

This sentence compares Ruth to someone who is drowning and it also compares love to water which can drown people.