Noun
Usually written in kana
1.  thing;  matter
2.  incident;  occurrence;  event;  something serious;  trouble;  crisis
3.  circumstances;  situation;  state of affairs
4.  work;  business;  affair
5.  after an inflectable word, creates a noun phrase indicating something the speaker does not feel close to
Suffix
Usually written in kana
6.  nominalizing suffix
7.  pretending to ...;  playing make-believe ...
Noun
Usually written in kana
8.  alias;  also known as;  otherwise known as;  or
as AことB (A = alias, B = real name)
9.  necessity;  need
as 〜ことはない
10.  you should ...;  I advise that you ...;  it's important to ...
as 〜ことだ