creep and crawl, extend and expand, joke around

[jiang]

Dear teachers,

I have four questions to ask:

No.1
The following are the definitions of creep:

1. to move slowly, quietly and carefully, usually in order to avoid being noticed:
2. In Ramdom House Webster's Dictionary of American English: move slowly with the body close to the ground on hands and knees.
It occurred to me the second meaning is the same with that of "crawl":
to move slowly withthe body stretched out along the ground or (of a human on hands and knees). I have no idea whether it is the difference between American English or British English or the meaning of the word "creep" has extended.
Then please read the following sentence:
He had lost both his legs. Nobody knew how he managed to crawl back home.
My question is: Can I replace "crawl" with "creep"?

No.2
The following is from Ramdom House Webster's Dictionary of American English:
extend: to strech or draw out; to make longer
expand: to strech out
Please read the sentence:
The snake expanded to its full length. My question is: Can I replace "expand" with "extend".
And in the sentence:
The railway will be further extended to link with the trans-Siberia railway in Russia.
Can I replace "extend" with "expand"?

No.3
I can say "joke about something" which means "say something amusing". Then I can also express the meaning by saying "joke around" with no object. Is that right? For example : He joked around instead of working. That means "He said amusing things instead of working". Is that right?

Looking forward to hearing from you.
Thank you in advance.

Jiang

[David L.]

1. No use saying 'far be it from me that I should disagree with mighty Random House': I do. A plant may creep along the ground, but then it has no legs. A human can creep on tip toe, so that 'body close to the ground' is not an essential part of the definition.
Referring to a person, 'crawl' means 'to move forward on the hands and knees or by dragging the body close to the ground.' Referring to a vehicle, it means 'move at an unusually slow pace'.
Hence, our expression - which we do not regard as tautological - 'Watch out for creepy-crawlies'.

2. 'extend' is to make longer, in length, or time.
'expand' is to make larger - as in 'your chest expands when you breath in'. It is not confined to 'length' - A balloon expands in all direction, a railway track is extended (specifically, made longer in length).

3. 'to joke about something' means to regard something as a source of amusement. This may be amusing, or joking about a situation/event that others see as serious and so joking about it may be inappropriate.
'to joke around' does not so much mean 'telling jokes' as acting in a clownish way, pulling pranks on people for general amusement of others. Do it, and you can expect the butt of your 'humour' not to be amused! At the same time, a person may say of another that he 'likes to joke around' and the smile on his face and tone of voice could suggest that his 'joking around' is within limits, and people may regard him as a funny guy with a relaxed style to him, rather than 'a serious type'. So, it depends.