Kennings

A kenning (Old Norse kenning [cʰɛnːiŋg], Modern Icelandic pronunciation [cʰɛnːiŋk]) is a circumlocution used instead of an ordinary noun in Old Norse and later Icelandic poetry. For example, Old Norse poets might replace sverð, the regular word for “sword”, with a compound such as ben-grefill “wound-hoe” (Egill Skallagrímsson: Höfuðlausn 8), or a genitive phrase such as randa íss “ice of shields” (Einarr Skúlason: ‘Øxarflokkr’ 9). The term kenning has been applied by modern scholars to similar figures of speech in other languages too, especially Old English.
http://en.wikipedia.org/wiki/Kenning

Examples:
bear : bee wolf : beowulf
blood : battle sweat
corpse : raven harvest
chieftain or king : breaker of rings
eyes : brow stars
http://en.wikipedia.org/wiki/List_of_kennings

My own:
computer : mind's work horse
sky : gaseous ceiling
car : wreaking wrecker

Interesting parallel:
In cognitive linguistics, metonymy refers to the use of a single characteristic to identify a more complex entity and is one of the basic characteristics of cognition. It is common for people to take one well-understood or easy-to-perceive aspect of something and use that aspect to stand either for the thing as a whole or for some other aspect or part of it.