Source : Webster's Revised Unabridged Dictionary (1913)

Thionyl \Thi"on*yl\, n. [Thionic + -yl.] (Chem.)
   The hypothetical radical {SO}, regarded as an essential
   constituent of certain sulphurous compounds; as, thionyl
   chloride.

Source : WordNet®

so
     adj 1: conforming to truth; "I wouldn't have told you this if it
            weren't so"; "a truthful statement" [syn: {so(p)}, {truthful}]
     2: marked by system; in good order; "everything is in order";
        "his books are always just so"; "things must be exactly
        so" [syn: {in order(p)}, {so(p)}]

so
     adv 1: to a very great extent or degree; "the idea is so obvious";
            "never been so happy"; "I love you so"; "my head aches
            so!"
     2: in order that; "he stooped down so he could pick up his hat"
     3: in such a condition or manner, especially as expressed or
        implied; "They're happy and I hope they will remain so";
        "so live your life that old age will bring no regrets"
     4: to a certain unspecified extent or degree; "I can only go so
        far with this student"; "can do only so much in a day"
     5: in the same way; also; "I was offended and so was he";
        "worked hard and so did she"
     6: in the way indicated; "hold the brush so"; "set up the
        pieces thus"; (`thusly' is a nonstandard variant) [syn: {thus},
         {thusly}]
     7: (usually followed by `that') to an extent or degree as
        expressed; "he was so tired he could hardly stand"; "so
        dirty that it smells"
     8: subsequently or soon afterward (often used as sentence
        connectors); "then he left"; "go left first, then right";
        "first came lightning, then thunder"; "we watched the late
        movie and then went to bed"; "and so home and to bed"
        [syn: {then}, {and so}, {and then}]
     9: in truth (often tends to intensify); "they said the car
        would break down and indeed it did"; "it is very cold
        indeed"; "was indeed grateful"; "indeed, the rain may
        still come"; "he did so do it!" [syn: {indeed}]

so
     n : the syllable naming the fifth (dominant) note of any musical
         scale in solmization [syn: {sol}, {soh}]

Source : Free On-Line Dictionary of Computing

SO
     
        1.  {Shift Out}
     
        2. Significant Other, almost invariably written abbreviated
        and pronounced /S-O/ by hackers.  Used to refer to one's
        primary relationship, especially a live-in to whom one is not
        married.
     
        [{Jargon File}]

so
     
         The {country code} for Somalia.
     
        (1999-01-27)