I think I remember an Australian once told me that "spam" was some kind of canned meat/ham, totally tasteless; and now, it sure means "junk mail". I have no idea about "foo"...
Hello almost everyday now, Pieanne. I found the same explanation for SPAM in my dictionary as the Australian told you above too but not the entry for "junk mail". Anyway, I learnt it means "junk mail" here. It is correct.
Foo is commonly used in programming on computers, when a coder can't be bothered to think of a variable name - for example, a coder might write ' int foo; foo = 2; '
. It's much like using 'x' in maths as an unknown number - 'foo' is a more popular choice in long, complex programs. It was also a word used by 'Mr T.' : He would often say "I pity the f