Merriam-Webster Collegiate Dictionary - the

 I. definite article  Etymology: Middle English, from Old English the, masculine demonstrative pronoun & definite article, alteration (influenced by oblique cases — as th?s, genitive — & neuter, th?t) of se; akin to Greek ho, masculine demonstrative pronoun & definite article — more at that  Date: before 12th century  1.  a. — used as a function word to indicate that a following noun or noun equivalent is definite or has been previously specified by context or by circumstance put ~ cat out  b. — used as a function word to indicate that a following noun or noun equivalent is a unique or a particular member of its class ~ President ~ Lord  c. — used as a function word before nouns that designate natural phenomena or points of ~ compass ~ night is cold  d. — used as a function word before a noun denoting time to indicate reference to what is present or immediate or is under consideration in ~ future  e. — used as a function word before names of some parts of ~ body or of ~ clothing as an equivalent of a possessive adjective how's ~ arm today  f. — used as a function word before ~ name of a branch of human endeavor or proficiency ~ law  g. — used as a function word in prepositional phrases to indicate that ~ noun in ~ phrase serves as a basis for computation sold by ~ dozen  h. — used as a function word before a proper name (as of a ship or a well-known building) ~ Mayflower  i. — used as a function word before a proper name to indicate ~ distinctive characteristics of a person or thing ~ John Doe that we know wouldn't lie  j. — used as a function word before ~ plural form of a surname to indicate all ~ members of a family ~ Johnsons  k. — used as a functon word before ~ plural form of a numeral that is a multiple of ten to denote a particular decade of a century or of a person's life life in ~ twenties  l. — used as a function word before ~ name of a commodity or any familiar appurtenance of daily life to indicate reference to ~ individual thing, part, or supply thought of as at hand talked on ~ telephone  m. — used as a function word to designate one of a class as ~ best, most typical, best known, or most worth singling out this is ~ life ~ pill — sometimes used before a personal name to denote ~ most prominent bearer of that name  2.  a.  (1) — used as a function word with a noun modified by an adjective or by an attributive noun to limit ~ application of ~ modified noun to that specified by ~ adjective or by ~ attributive noun ~ right answer Peter ~ Great  (2) — used as a function word before an absolute adjective or an ordinal number nothing but ~ best due on ~ first  b.  (1) — used as a function word before a noun to limit its application to that specified by a succeeding element in ~ sentence ~ poet Wordsworth ~ days of our youth didn't have ~ time to write  (2) — used as a function word after a person's name to indicate a characteristic trait or notorious activity specified by ~ succeeding noun Jack ~ Ripper  3.  a. — used as a function word before a singular noun to indicate that ~ noun is to be understood generically ~ dog is a domestic animal  b. — used as a function word before a singular substantivized adjective to indicate an abstract idea an essay on ~ sublime  4. — used as a function word before a noun or a substantivized adjective to indicate reference to a group as a whole ~ elite  II. adverb  Etymology: Middle English, from Old English thy? by that, instrumental of th?t that  Date: before 12th century  1. than before ; than o~rwise — used before a comparative none ~ wiser for attending  2.  a. to what extent ~ sooner ~ better  b. to that extent ~ sooner ~ better  3. beyond all o~rs likes this ~ best  III. preposition  Etymology: 1~  Date: 15th century per 2 a dollar ~ dozen THE-  or theo-  combining form  Etymology: Middle English theo-, from Latin, from Greek ~, theo-, from theos god ; God theism theocentric