Word Study
than
CIDE DICTIONARY
than, conj. [OE. than, thon, then, thanne, thonne, thenne, than, then, AS. &edh;anne, &edh;onne, &edh;ænne; akin to D. dan, OHG. danne, G. dann then, denn than, for, Goth. þan then, and to E. the, there, that. See That, and cf. Then.].
A particle expressing comparison, used after certain adjectives and adverbs which express comparison or diversity, as more, better, other, otherwise, and the like. It is usually followed by the object compared in the nominative case. Sometimes, however, the object compared is placed in the objective case, and than is then considered by some grammarians as a preposition. Sometimes the object is expressed in a sentence, usually introduced by that; as, I would rather suffer than that you should want. [1913 Webster]
"Behold, a greater than Solomon is here." [1913 Webster]
"Which when Beelzebub perceived, than whom,
Satan except, none higher sat." [1913 Webster]
Satan except, none higher sat." [1913 Webster]
"It's wiser being good than bad;
It's safer being meek than fierce;
It's fitter being sane than mad." [1913 Webster]
It's safer being meek than fierce;
It's fitter being sane than mad." [1913 Webster]
than, adv.
Then. See Then. Gower. [1913 Webster]
"Thanne longen folk to gon on pilgrimages." [1913 Webster]
OXFORD DICTIONARY
than, conj.
1 introducing the second element in a comparison (you are older than he is; you are older than he).
1 introducing the second element in a comparison (you are older than he is; you are older than he).
Usage
It is also possible to say you are older than him, with than treated as a preposition, esp. in less formal contexts.
2 introducing the second element in a statement of difference (anyone other than me).
2 introducing the second element in a statement of difference (anyone other than me).
Etymology
OE thanne etc., orig. the same word as THEN
THESAURUS
than
alias, as compared with, aside from, bar, barring, beside, besides, by comparison with, compared with, contrarily, else, elsewise, ex, except, except for, excepting, excluding, exclusive of, in comparison with, in other respects, in other ways, leaving out, let alone, omitting, or else, other than, otherwise, outside of, over against, precluding, save, save and except, saving, taken with, unless, withoutFor further exploring for "than" in Webster Dictionary Online