What is lexicology?
Lexicology is the study of lexis or stock of words in a language. We will also use the word vocabulary interchangeably with lexis. Take note that lexis and vocabulary are non-count nouns (although occasionally, you could talk about vocabularies, this would be unusual); if you need to refer to individual items, you should talk about lexical items or vocabulary items. You might also encounter the term lexicon, which (unfortunately) can be used in a couple of ways; firstly, it can be used as a more technical version of lexis; many people use it synonymously with dictionary. What must be remembered is that any dictionary can never be comprehensive in its listing of the lexis of a particular language. (You might also encounter the term lexicography which is the study of dictionaries.)
We have used the word word extensively, and there is a commonsensical obviousness to it. At this stage we will take the orthographic definition of word, and say that it is an item that, in writing, is usually separated from other items by a space. Another issue that sometimes arises is whether bring and brought are two separate words. We shall say that they are two separate word-forms, but that they represent one lexeme.
But what exactly is it about words that a lexicologist will be concerned about?
[1820s, from Greek lexikós of words, -logia study] An area of language study concerned with the nature, meaning, history and use of words and word elements and often also with the critical description of lexicography (McArthur 1992: 602)
That branch of knowledge which treats of words, their form, history, and meaning. (OED online)
1 the study of the history and meaning of words. 2 the analytical study of lexicography. (Chambers 21st century dictionary, 1996)
The definitions suggest that we should be concerned about:
The Oxford English Dictionary is one that is organised on historical principles. What does that mean? Compare this entry of atlas with the one from Collins Cobuild.
Forms: Pl. atlases.
Etymology: < Latin Atlās, -antem, < Greek Ἄτλας, -αντα; name of one of the older family of gods, who was supposed to hold up the pillars of the universe, and also of the mountain in Libya that was regarded as supporting the heavens. Hence the various fig. uses.
1. a. One who supports or sustains a great burden; a chief supporter, a mainstay.
1589 Nashe in Greene's Menaph. (Arb.) Ded. 17, I dare commend him to all that know him, as‥the Atlas of Poetrie.
1618 Barneveld's Apol. C iv b, You‥make your selfe the Atlas, and sustainer of the whole state of Holland.
1883 M. Howland in Harper's Mag. Mar. 598/1 We brokers are the Atlases that bear the world upon our shoulders.
b. Archit. (See atlantes n.)
2. Physiol. The first or uppermost cervical vertebra, which supports the skull, being articulated above with the occipital bone. (So in Greek.)
1699 Philos. Trans. (Royal Soc.) 21 180 The Union by the Atlas, is not so firm and compact as in the other Vertebræ.
1842 E. Wilson Anatomist's Vade Mecum 9 The Atlas is a simple ring of bone, without body, and composed of arches and processes.
3. A collection of maps in a volume. [This use of the word is said to be derived from a representation of Atlas supporting the heavens placed as a frontispiece to early works of this kind, and to have been first used by Mercator in the 16th cent.]
1636 (title) Atlas; or a geographic description of the world, by Gerard Mercator and John Hondt.
1641 J. Evelyn Mem. (1857) I. 28 Visited the famous Hondius and Bleaw's shop, to buy some maps, atlasses, etc.
1729 Flamsteed (title) Atlas Cœlestis.
1812 R. Woodhouse Elem. Treat. Astron. ix. 63 Celestial Atlases also, or maps of the Heavens.
4. A similar volume containing illustrative plates, large engravings, etc., or the conspectus of any subject arranged in tabular form; e.g. ‘an atlas of anatomical plates,’ ‘an ethnographical atlas’.
1875 C. D. E. Fortnum Maiolica vi. 53 The details of all these methods are illustrated on the 3rd table of his atlas of plates.
5. A large square folio resembling a volume of maps; also called atlas-folio.
6. A large size of drawing-paper.
1712 Act 10 Anne in London Gaz. No. 5018/3, For all Paper called Atlas fine 16s. per Ream, Atlas ordinary 8s.
1879 E. Spon Workshop Receipts 1, Atlas, 33 × 26 inches.
atlas beetle n. a gigantic olive-green lamellicorn beetle ( Chalcosoma atlas), found in the East.
Atlas-like adj. and adv. like, or after the manner of, Atlas.
?1614 W. Drummond Song: It was the time in Poems, That Atlas-like it seem'd the Heauen they beared.
atlas moth n. (Saturnia atlas) a very large foreign moth.
1868 J. G. Wood Homes without Hands xiv. 280 That magnificent insect the Atlas Moth.
Etymology: < (ultimately) Arabic aṭlas ‘smooth, bare,’ thence ‘smooth silk cloth,’ < ṭalasa...
arch. or Obs.
A silk-satin manufactured in the East.
1687 London Gaz. No. 2273/7, Atlasses 549 pieces.
1703 T. Baker Tunbridge-walks i. sig. B1v, Fat City-Ladies with tawdry Atlasses.
c1710 in J. Ashton Social Life Reign of Queen Anne (1882) I. 167 One Purple and Gold Atlas Gown.
1757 J. H. Grose Voy. E.-Indies x. 188 Their atlasses, or sattins flowered with gold or silver.
/&tl@s/ atlases. N-COUNT. An atlas is a book of maps of all the areas in the world. (BAND 5 – the band of least frequent words)
The Cobuild account is clearly shorter, but like the OED, gives the form, including the plural form and the pronunciation in IPA. Cobuild gives some information about the use by incorporating it in a sentence, and giving the item a grammatical label (N-COUNT, meaning it is a noun, and is countable). Finally, it gives information about word frequency.
The OED gives no information about frequency; word-class labels are used. There are numbered senses (meanings) of the word (including archaic and specialised ones), arranged in chronological order in which the senses began to be used. There is also an etymological entry and historical examples of the use of the item. Therefore, the OED is based on historical principles in that:
The Cobuild is gives a more synchronic account of the lexical item.