What is "the"

The \The\ ([th][=e]), v. i. See Thee. [Obs.]
--Chaucer.
--Milton.

The \The\ ([th][=e], when emphatic or alone; [th][-e], obscure before a vowel; [th]e, obscure before a consonant; 37), definite article. [AS. [eth][=e], a later form for earlier nom. sing. masc. s[=e], formed under the influence of the oblique cases. See That, pron.] A word placed before nouns to limit or individualize their meaning.

Note: The was originally a demonstrative pronoun, being a weakened form of that. When placed before adjectives and participles, it converts them into abstract nouns; as, the sublime and the beautiful.
--Burke. The is used regularly before many proper names, as of rivers, oceans, ships, etc.; as, the Nile, the Atlantic, the Great Eastern, the West Indies, The Hague. The with an epithet or ordinal number often follows a proper name; as, Alexander the Great; Napoleon the Third. The may be employed to individualize a particular kind or species; as, the grasshopper shall be a burden.
--Eccl. xii. 5.

The \The\, adv. [AS. [eth][=e], [eth][=y], instrumental case of s[=e], se['o], [eth][ae]t, the definite article. See 2d The.] By that; by how much; by so much; on that account; -- used before comparatives; as, the longer we continue in sin, the more difficult it is to reform. ``Yet not the more cease I.''
--Milton.

So much the rather thou, Celestial Light, Shine inward, and the mind through all her powers Irradiate.
--Milton.

definite article, late Old English þe, nominative masculine form of the demonstrative pronoun and adjective. After c.950, it replaced earlier se (masc.), seo (fem.), þæt (neuter), and probably represents se altered by the th- form which was used in all the masculine oblique cases (see below).\n

\n\n\n\n\nMasc.\nFem.\nNeut.\nPlural\n\n\nNom.\nse\n\nseo\nþæt\nþa\n\n\nAcc.\nþone\nþa\nþæt\nþa\n\n\n\nGen.\nþæs\nþære\nþæs\nþara\n\n\nDat.\nþæm\n\nþære\nþæm\nþæm\n\n\nInst.\nþy, þon\n
--\nþy, þon\n
--\n\n\n\n

\nOld English se is from PIE root *so- "this, that" (cognates: Sanskrit sa, Avestan ha, Greek ho, he "the," Irish and Gaelic so "this"). For the þ- forms, see that. The s- forms were entirely superseded in English by mid-13c., excepting a slightly longer dialectal survival in Kent. Old English used 10 different words for "the" (see table), but did not distinguish "the" from "that." That survived for a time as a definite article before vowels (that one or that other).\n

\nAdverbial use in the more the merrier, the sooner the better, etc. is a relic of Old English þy, the instrumentive case of the neuter demonstrative (see that).

Etymology 1 article 1 (non-gloss definition definite Definite http://en.wikipedia.org/wiki/grammatical%20article that implies necessarily that an entity it articulates is presupposed; something already mentioned, or completely specify specified later in that same sentence, or assumed already completely specified.) (from 10th c.) 2 Used before an object considered to be unique, or of which there is only one at a time. (from 10th c.) 3 (non-gloss definition: With a superlative, it and that superlative refer to one object.) (from 9th c.) 4 (non-gloss definition: Introducing a term to be taken generically; preceding a name of something standing for a whole class.) (from 9th c.) 5 (non-gloss definition: Used before an adjective, indicating all things (especially persons) described by that adjective.) (from 9th c.) 6 Used to indicate a certain example of (a noun) which is most usually of concern, or most common or familiar. (from 12th c.) 7 (non-gloss definition: Used before a body part (especially of someone previously mentioned), as an alternative to a possessive pronoun.) (from 12th c.) 8 (non-gloss definition: When stressed, indicates that it describes an object which is considered to be best or exclusively worthy of attention.) (from 18th c.) Etymology 2

adv. 1 With a comparative or ''more'' and a verb phrase, establishes a parallel with one or more other such comparatives. 2 (non-gloss definition: With a comparative, and often with ''for it'', indicates a result more like said comparative. This can be negated with ''none''.)