'bus

You may see this spelling in older texts. Until well into the second half of the twentieth century, it was the orthodox way to write the name of the public service vehicle that is now simply bus. Do not use the older form.

(The word bus was written as 'bus to show the reader that the writer was well educated enough to know that it is an abbreviation of the Latin word omnibus. This means 'for all'.)

See archaic contractions, and the similar formations 'phone and 'plane.