The word synecdoche is derived from the Greek word "synekdochḗ," in which "syn-" stands for "together" and "ekdochē" for "interpretation." The term is implied as a figurative form, in which the part reflects the whole (thirty sail for thirty ships) and the whole is reflected by the part (a Croesus for a rich person).

The semantic definition of this linguistic tool is a turn of meanings within a single semantic field, in which one element is represented by another one, the extension of which is semantically broader or narrower.

The contextual significance of synecdoche is determined by its wide range of possible uses. Instead of listing all members of an organization, or a football club, there is an option to reach brevity by capturing the essence. This literary technique refers to the concept of associative and referential thinking, so the reader automatically grasps the connectivity between all the related elements.

To identify this literary technique in the context, there are several forms of wholes and parts to be considered:
●Pars pro toto is the form, in which an element or a part of something is referred to the entire whole. Saying England and Great Britain, we usually assume the United Kingdom.
●Totum pro parte is the form, in which the whole is treated as an element or a part. For example, the Internet as a system of connected networks stands for the broader meaning of the World Wide Web as a database of documents that can be accessed via the Internet.

There are also some forms of this literary technique appealing to specific cases:
●A physical structure and its parts: "All eyes on the teacher!" is a part-to-whole synecdoche form, in which "eyes" reflect the students of which they are physically a part. Note that not every part of appearance is suitable for synecdoche. Otherwise, a phrase or a sentence may sound offensive to potential readers or listeners.
●An item and the material: “Don’t play with fire!” is a form of this technique, in which fire stands for matches, a tool for starting a fire, although its meaning is much more broader than just the material.
●A container and what it contains: "Can I give you a plate?" refers not to the plate itself, but to the food on it.
●A category and the elements of that category: "Canada left without gold" is a whole-to-part form, in which the larger category of "Canada" is referred only to the Canadian athletes.

Synecdoche can be addressed as a type of symbolism that focuses on the part rather than the whole. The major idea hiding behind this concept is that the part itself is crucial for an overall understanding of a phrase. Thus, "a human brain" is a part of a human body that we associate with our talents and skills, although it is obvious that the entire person is involved in the thinking and working process.

Using this literary tool, the author can tailor new associations in such a way that would be easy to grasp despite their stylistic complexity. Thus, this literary tool is considered as a class of metonymy while both devices build conceptual links by replacing one thing by another. Although compared to metonymy, part-to-whole and whole-to-part connections of synecdoche are not only conceptually but also physically related to each other. Thus, this literary device addresses some parts of a thing, instead of its attributes or the whole. In metonymy, the exchange is observed between several related objects while in synecdoche, the exchange is conducted between two associated concepts. Nevertheless, some theorists are still not sure how to classify these two literary devices. The idea to treat synecdoche as just one kind of metonymy is still in dispute.

Having some associations with personification, this literary device provides a non-living thing with some human features, such as in "money is coming to the wrong hands." Here, the word "hands" reflects a human aspect, although it belongs to the opposite group.

This figure of speech can often be found in idioms, colloquial expressions, and slang. For example, "Great wheels" is an everyday slang, in which "wheels" reflect the vehicle that they are a part of. Thus, we can use synecdoche if we call an item what it is made out of instead of its actual name. Oftentimes, synecdoche can be used by authors striving to make their speech more realistic. In addition, journalists are fond of using synecdoche. When they examine one school or business unit, they tend to treat it as typical of all such things.

Synecdoche is widely applied in literature, including prose and poetry to draw out a language elevation effect. Layering numerous meanings onto a single word, this literary device makes entire phrases sound more meaningful, poetic, and complex. Shakespeare in his "Macbeth" creates a strong voice for characters by referring to synecdoche. The phrase "Take thy face hence" sounds much more convincing compared to simply saying "You can go now."

The Summary
Synecdoche is a literary technique based on the idea of reflecting the part via the whole and vice versa. Even though theorists are still in some doubt whether to treat this literary tool independently or as a part of more complex literary forms, there is one clear nuance to remember. Synecdoche addresses a "structural" part of the thing, while, for example, metonymy addresses the part that might be connected to the thing but not as its structural element.