the |šē; šə| [called the definite article ]
adjective

1 denoting one or more people or things already mentioned or assumed to be common knowledge : what's the matter? | call the doctor | the phone rang. Compare with a .
• used to refer to a person, place, or thing that is unique : the Queen | the Mona Lisa | the Nile.
• informal denoting a disease or affliction : I've got the flu.
• (with a unit of time) the present; the current : dish of the day | man of the moment.
• informal used instead of a possessive to refer to someone with whom the speaker or person addressed is associated : I'm meeting the boss | how's the family?
• used with a surname to refer to a family or married couple : the Johnsons were not wealthy.
• used before the surname of the chief of a Scottish or Irish clan : the O'Donoghue.

2 used to point forward to a following qualifying or defining clause or phrase : the fuss that he made of her | the top of a bus | I have done the best I could.
• (chiefly with rulers and family members with the same name) used after a name to qualify it : George the Sixth | Edward the Confessor | Jack the Ripper.

3 used to make a generalized reference to something rather than identifying a particular instance : he taught himself to play the violin | worry about the future.
• used with a singular noun to indicate that it represents a whole species or class : they placed the African elephant on their endangered list.
• used with an adjective to refer to those people who are of the type described : the unemployed.
• used with an adjective to refer to something of the class or quality described : they are trying to accomplish the impossible.
• used with the name of a unit to state a rate : they can do 120 miles to the gallon.

4 enough of (a particular thing) : he hoped to publish monthly, if only he could find the money.

5 (pronounced stressing “the”) used to indicate that someone or something is the best known or most important of that name or type : he was the hot young piano prospect in jazz.

6 used adverbially with comparatives to indicate how one amount or degree of something varies in relation to another : the more she thought about it, the more devastating it became.
• (usu. all the ——) used to emphasize the amount or degree to which something is affected : commodities made all the more desirable by their rarity.

ORIGIN Old English (Northumbrian and North Mercian dialects) thē; related to Dutch de, dat, and German der, die, das.

USAGE
The article the is usually pronounced |šə|before a consonant sound (: please pass the potatoes) and |šē|before a vowel sound ( | please pass the asparagus). Regardless of consonant and vowel sounds, when the desired effect following the is to emphasize exclusivity, the pronunciation is |šē|:: she's not just any expert in vegetation management, she's the expert.