The selection of lexical units for inclusion

excel / ɪksel / verb [intransitive]
to do something extremely well:
We aim to give every student the opportunity to excel.
excel in/at: Robbie had always excelled at sport.
excel yourself
1 to do something much better than you usually do
2 HUMOROUS used when someone has in fact done even worse than they usually do
(2)
excel verb
past tense and past participle excelled, present participle excelling
1 [intransitive, not in progressive] to do something very well, or much better than most people
excel at/in
Rick has always excelled at foreign languages.
2 excel yourself British English to do something better than you usually do:
Graham has excelled himself with the new exhibition.
(4) The selection and arrangement of word-meanings. There are at least three different ways in which the word meanings are arranged: a) in the historical order, i.e. in the sequence of their historical development; b) in the empirical or actual order, i.e. in conformity with their frequency of use, i.e. with the most common meaning first; c) in the logical order, i.e. according to their logical connection.
In different dictionaries the problem of arrangement is solved differently. For example, the general principle on which meanings in the New Oxford Dictionary of English are organized is that each word has at least one core meaning, to which a number of submeanings can be attached. Core meanings, as the authors of the dictionary point out, represent typical, central uses of the word in question in modern Standard English. It is the meaning accepted by native speakers as the one that is most established as literal and central.
In many dictionaries meanings are generally organized by frequency of use, but sometimes the primary meaning comes first if this is considered essential to a correct understanding of derived meanings.
(5) The definition of meanings. Meanings of words may be defined in different ways: a) by means of linguistic definitions that are only concerned with words as speech material. They are used in the majority of entries; b) by means of encyclopedic definitions that are concerned with things for which the words are names; c) by means of synonymous words and expressions; d) by means of cross-references.
The choice of this or that type of definition depends, as a rule, on the nature of the word, i.e. usually the part of speech the word belongs to, and on the aim of the dictionary and its size. Encyclopedic definitions, for example, are typical of nouns, especially proper nouns and terms. They play a very important role in unabridged dictionaries. Synonyms are used most often to define verbs and adjectives. They are used in shorter dictionaries usually for economizing space. Cross-references are resorted to define some derivatives, abbreviations and variant forms.
(6) The illustrative material. The presentation of illustrative material depends on the type of the dictionary and on the aim the compilers set themselves. They can illustrate the first and the last known occurrences of the entry word, the successive changes in its meaning, as well as graphic and phonetic forms, the typical patterns and collocations; they place words in a context to clarify their meanings and usage.
Illustrative examples can be drawn from different sources, e.g. literature classical or contemporary, or can be constructed by the compilers themselves. For example, in the Longman Dictionary of Contemporary English illustrative examples are based on analysis of the authentic language in the Longman Corpus Network.
Some dictionaries indicate the author, the work, the page, verse, or line, and the precise date of the publication, some indicate only the author to give at least basic orientation about the time when the word occurs.