totum pro parte
Definition - A figure of speech where a part is referred to by mentioning the whole.
Note: Its opposite is pars pro toto, a figure of speech where the whole is referred to by mentioning one of its parts.

Example -

(1) When you say that someone is a drinker, you mean that he drinks alcohol excessively, not that he drinks all types of fluids.
(2) When an American says "God Bless America," he means "God Bless the United States"; he's not blessing Canada or Argentina, although both of those countries are part of America.

Etymology -
In Latin the phrase means "the whole for the part."

Please comment