before a vowel adj. & adv.
adj. (called the definite article) 1 denoting one or more persons or things already mentioned, under discussion, implied, or familiar (gave the man a wave; shall let the matter drop; hurt myself in the arm; went to the theatre). 2 serving to describe as unique (the Queen; the Thames). 3 a (foll. by defining adj.) which is, who are, etc. (ignored the embarrassed Mr Smith; Edward the Seventh). b (foll. by adj. used absol.) denoting a class described (from the sublime to the ridiculous). 4 best known or best entitled to the name (with the stressed: no relation to the Kipling; this is the book on this subject). 5 used to indicate a following defining clause or phrase (the book that you borrowed; the best I can do for you; the bottom of a well). 6 a used to indicate that a singular noun represents a species, class, etc. (the cat loves comfort; has the novel a future?; plays the harp well). b used with a noun which figuratively represents an occupation, pursuit, etc. (went on the stage; too fond of the bottle). c (foll. by the name of a unit) a, per (5p in the pound; $5 the square metre; allow 8 minutes to the mile). d colloq. or archaic designating a disease, affliction, etc. (the measles; the toothache; the blues). 7 (foll. by a unit of time) the present, the current (man of the moment; questions of the day; book of the month). 8 Brit. colloq. my, our (the dog; the fridge). 9 used before the surname of the chief of a Scottish or Irish clan (the Macnab). 10 dial. (esp. in Wales) used with a noun characterizing the occupation of the person whose name precedes (Jones the Bread).
adv. (preceding comparatives in expressions of proportional variation) in or by that (or such a) degree; on that account (the more the merrier; the more he gets the more he wants). all the in the full degree to be expected (that makes it all the worse). so much the (tautologically) so much, in that degree (so much the worse for him).
[ (adj.) OE, replacing se, seo, tht (= THAT), f. Gmc: (adv.) f. OE thy, the, instrumental case ]