SYNECDOCHE
synecdoche
(noun) substituting a more inclusive term for a less inclusive one or vice versa
Source: WordNet® 3.1
Etymology
Noun
synecdoche (countable and uncountable, plural synecdoches)
(figure of speech) A figure of speech that uses the name of a part of something to represent the whole, or the whole to represent a part.
Hyponyms: pars pro toto, totum pro parte
Hypernym: metonymy
(rhetoric) The use of this figure of speech.
Synonym: synecdochy
Usage notes
Technically, a synecdoche is a part of the referent while a metonym is connected or associated but not necessarily a part of it.
Source: Wiktionary
Syn*ec"do*che, n. Etym: [L. synecdoche, Gr. (Rhet.)
Definition: A figure or trope by which a part of a thing is put for the
whole (as, fifty sail for fifty ships), or the whole for a part (as,
the smiling year for spring), the species for the genus (as,
cutthroat for assassin), the genus for the species (as, a creature
for a man), the name of the material for the thing made, etc. Bain.
Source: Webster’s Unabridged Dictionary 1913 Edition