This is what we call a metonymical extension - where a word extends its meaning to something contiguous with its original meaning (and may or may not eventually abandon its original meaning) e.g. "glass" means both the substance and something such as a drinking vessel made of glass.    From Wordnik.com.  [Quote of the Day] Reference

Many reasons might be given of this metonymical expression, that I shall not now insist on.    From Wordnik.com.  [Of the Mortification of Sin in Believers] Reference

Secondly, It is not a presence by virtue of a metonymical denomination, or an expression of the cause for the effect, that is intended.    From Wordnik.com.  [Pneumatologia] Reference

Wherefore this expression is metonymical, that being spoken of the cause which is proper to the effect; the Spirit being said to be poured forth, because his graces are so.    From Wordnik.com.  [Pneumatologia] Reference

The first mode is synecdochical, the second common, the third metonymical; I add that the third might properly be called catachrestic if we attend to the just distinction of these members.    From Wordnik.com.  [The Works of James Arminius, Vol. 3] Reference

Moreover, this form of speech, that the stone shall be Beth-el, is metonymical; as we are sanctioned, by common usage, to transfer to external signs what properly belongs to the things represented.    From Wordnik.com.  [Commentary on Genesis - Volume 2] Reference

Sure, he provides plenty of linguistic examples of the types of mappings metaphorical, metonymical, polysemic, etc., and even the types of inferences made, but no description of how any of this occurs.    From Wordnik.com.  [Archive 2004-09-01] Reference

The word lo'gos itself has at times the metonymical sense here given to it, and therefore en anoi'xei tou sto'mato's is most naturally taken without emphasis as equivalent to, when I open my mouth, i.e. when called upon to speak.    From Wordnik.com.  [A Commentary on the Epistle to the Ephesians] Reference

The presentation of The Accident, too, is unsatisfying though less annoying than the sexism because it is so carefully explained, so unambiguous that all its potential metaphorical or metonymical power is stripped away and it just sits there, a big, lunky, distracting, awkward bit of background detail, a Thing that could have been, instead, an evocation.    From Wordnik.com.  [Archive 2007-02-01] Reference

His "metonymical, ironical, metaphorical, and synecdochal instruments of elocution, in all their several kinds, artificially affected, according to the nature of the subject, with emphatical expressions in things of great concernment, with catachrestical in matters of meaner moment; attended on each side respectively with an epiplectic and exegetic modification, with hyperbolical, either epitatically or hypocoristically, as the purpose required to be elated or extenuated, they qualifying metaphors, and accompanied with apostrophes; and, lastly, with allegories of all sorts, whether apologal, affabulatory, parabolary, aenigmatic, or paroemial"?.    From Wordnik.com.  [The Atlantic Monthly, Volume 04, No. 21, July, 1859] Reference