[1] Giles started compilation after being rebuked for criticizing mistranslations in Samuel Wells Williams' (1874) A Syllabic Dictionary of the Chinese Language.

[4] In 1867, Giles passed the competitive Foreign Office examination for a Student Interpretership in China, and began studying the Chinese language at Peking.

[18] As Giles explains in his previously unpublished (c. 1918–1925) typescript memoirs, [The] review was of Dr Williams' Syllabic Dictionary (Evening Gazette, 16 Sept., 1874), for which I was freely bespattered with abuse from all American quarters.

I showed up a multiplicity of absurd blunders and equally egregious omissions; and I wound up with these prophetic words: "We do not hesitate to pronounce Dr Williams the lexicographer, not for the future, but of the past."

Herbert Giles continued working on his Chinese–English dictionary for 15 years until 1889 when the Foreign Office granted his request to be stationed as Consul at Ningpo, where the workload was light and he could prepare the manuscript for press.

volumes comprising a 46-page front matter (9-page Preface and 32-page Philological Essay) and the 1415-page dictionary, printed in triple columns, beginning with 60 pages of tables.

[24] For the subsequent two decades, Giles diligently worked "to correct mistakes, cut out duplicates and unnecessary matter, prepare revised Tables, and add a very large number of new phrases, taken from my reading in modern as well as in ancient literature".

After consulting with Giles, Satow supported the new publication in a letter dated May 29, 1903, stating "I understand from the author that the new edition is not a mere reproduction of the first.

Mistakes have been corrected, further meanings have been added to many characters, frequent cross-references have been introduced, and no fewer than ten thousand new phrases have been distributed over the entries as they now stand, chiefly drawn from sources in which the Dictionary has been found to be deficient".

He decided to number every head entry—an improvement lacking in the earlier dictionaries of Morrison, Medhurst, and Williams—in order to facilitate internal cross-referencing and make it easier for users to find characters.

[36] Giles subsequently worked for 20 years revising and adding "a vast number of compounds and phrases" to the 1912 second edition, which contains 10,926 head entries (67 more) plus 2,922 variants, also totaling 13,848.

Giles' dictionary abbreviates the nine varieties ("dialects") by their initial letter: C. Cantonese, H. Hakka, F. Foochow, W. Wênchow, N. Ningpo, P. Pekingese, M. "Mid-China", Y. Yangchow, and S. Ssuch'uan, as well as in K. Korean, J. Japanese, and A. Annamese languages.

In the first edition, Giles uses 5 to denote alternate tonal pronunciations that he had heard, eruditely described as "tra cotanto senno" (Italian for "amid such wisdom", from Dante's Inferno).

Despite the historical fact that the "entering" tone had already ceased to exist in 19th-century Beijing pronunciation, Norman notes that early Chinese–English dictionaries were "much concerned with including it".

Dictionary pages are formatted in three columns, each split between the head entry character, number, and pronunciations on the left, and the translation equivalents ("definitions"), cross references, and subentries of terms on the right.

The dictionary's approximately "hundred thousand examples" diversely range from the "best and highest planes of Chinese thought" to everyday words and nursery rhymes.

[40] The Chinese character 道 for dào "way; path; say; the Dao" or dǎo "guide; lead; conduct; instruct; direct" (or 導 clarified with Radical 41 寸 "thumb; inch") is a good litmus test for a dictionary because it has two pronunciations and complex semantics.

The sample entry from Giles' dictionary for tao4 道4 (10,780) gives the character and number over pronunciations from Cantonese tou to Vietnamese dau on the left, and the translation equivalents and examples on the right.

[41] The 1912 second edition adds references to Christian Greek scriptural λόγος logos, Thomas William Kingsmill's (1899)[42] Daodejing translation comparing dào with Sanskrit mārga "path; (Buddhist) paths to liberation", the meaning "principles" under mou 謀2 (8032) "to plot; to scheme", "Tai chi" 太極 under 極2* (859), dàotái 道臺 "(historical) the magistrate of a dào district/circuit", and the syntactic use of 道 as a classifier or measure word for rivers/topics/etc.

The first edition 道4[43] entry gives 230 examples of words and phrases for tao4 "way; path" (e.g., "黃道 the ecliptic; good luck; a lucky day; the conjunction of the sun and moon; in Taoist language, the state of unconscious innocence, as of an unborn babe"), and "Read tao3.

The second edition[44] gives 255 examples (for instance, adding "一達謂之道 that which passes through is called tao", quoting the Shuowen Jiezi dictionary definition of dào) and "Read tao3.

Herbert Giles created the first Chinese–English encyclopedic dictionary in two ways, with comprehensive explanations under head entries and with informative tables.

For instance, the character 長 can be pronounced cháng "long; lasting", zhǎng "grow up; increase", or zhàng "plenty; surplus": Wade–Giles ch'ang2, chang3 and chang4, respectively.

[46] The English sinologist Charles Aylmer, who first published The Memoirs of H. A. Giles from a Cambridge University Library manuscript, gives a balanced evaluation on the dictionary.

Second, Giles failed to indicate stylistic level, which he justifies on the "(somewhat specious) grounds" that, "No division of phraseology into classical and colloquial has been made, for the simple reason that no real line of demarcation exists.

Today the dictionary is most often cited as the locus classicus of the Wade–Giles romanisation system, for which the name of Giles is widely known even to non-specialists.

Apart from this, its practical use is mainly as a repository of late Ch'ing bureaucratic phraseology, though it is replete with fascinating nuggets of information and is a wonderful book for browsing.

[27] The English sinologist and historian Endymion Wilkinson says Giles' dictionary is "still interesting as a repository of late Qing documentary Chinese, although there is little or no indication of the citations, mainly from the Kangxi zidian)".