(Adapted from: http://www.quanjing.com/share/gwf107018.html)
There are some differences between a Chinese character and an English word, in terms of how it is used to describe a meaning if, put other things equal (e.g., the words chosen here can both mean real meanings, rather than abstract concepts like elitism or communism, whose interpretations are built upon the combination of other real meanings, rather than mean them themselves)
Take the Chinese character <粹> and an English word <reading> here for instance. <Reading> is a word whose pronunciation is fixed upon how it is written: R-ea-ding (Each part has its own fixed pronunciation, though put into different combinations it may change: For example <ea> pronounces differently in <reading> from it does in <swear>). It is similar here that in <粹> its pronunciation is partly decided by the part <卒> . Like how <ea> acts in English words, when combining with different parts, the pronunciation of <卒> suits the integral Chinese character and thus changes (for example in <猝> and <粹>, <卒> does not pronounce the same).
However unlike the word <reading>, whose <r> and <d> parts do not themselves mean anything that contribute to what <reading> means (skills of understanding a literature or skills of interpretations; here the form <ing> is a suffix to change a verb to a noun—it’s irrelevant from the discussion here), the <米> in <粹> plays a very significant role in understanding the meaning of <粹>: <米> originally means rice. When combining <卒>, it makes the meaning more specific, while keeping part of the pronunciation of <卒>. Thus <粹> is used to call a type of rice that is of essential quality through a purified process. —It’s an essence.
This may be the reason when again <粹> is combined with other Chinese characters and form a short phrase/word, it keeps that original meaning—-the meaning related to where these Chinese characters were originally created—Chinese Agricultural Civilization:
<国粹>: The essence of a country/nation, the representation of the best in that country/nation. In China, what have been called <国粹> include <Chinese Medicine> (中华医药), Peking Opera/Jing Ju (京剧).
<民粹>: The political stance to serve the benefits of the mass, at the destruction/unbelief against the elitists and their according power structure (because they are regarded as corruptive and not worth trustworthy). Here the word adopts the <粹> for its meaning of purification, and follows the only___ can___ logic.
<纳粹>: The direct translation of NAZI into Chinese, based upon the similarity of their pronunciations. Nonetheless, <粹> is selected rather than other Chinese characters that have the same pronunciations. This translation is in accurate accordance with the NAZI’s deeds during the Second World War—purifying/exterminating process at the sacrifice of other non-German ethnic groups, to reach the so-called glorious essence–the superior uniqueness.