Question

Lying at home in bed is the thing _I_ am afraid of

what type of figure of speech is this

Answer 1

part of speech or figure of speech? Parts of speech are more grammatical. For example, nouns, pronouns, adjectives, ect. (there's eight). Figures of speech are more poetic. These are smilies, metaphors, hyperboles, and such.

If this sentence is a metaphor, I cannot tell how it can be so. The idea behind the metaphor is to connect two words in order to compare them.
For example: "My dog is a rat. The dog snoops around for food."
hopefully my example is good enough, if not, i'll take an example from here. http://specialed.about.com/od/literacy/a/figurative.htm
"You're such an airhead. It's bursting with flavor."