In relation to hours worked in an employment contract, what can 'typically' mean?

If employment contract says '40 hour week, typically 9-5' does this mean your employer can make you work those hours even if you have a verbal agreement to work, for example, 8.30 - 4.30.

Is that all it says? Does it not give days of work or band-widths of hours? Do you have flexible working hours?
From what you have said, yes it would be fairly easy for your employer to change your hours, given that you only have a verbal agreement to work 8.30 - 4.30.
If you could get something in writing/e-mail then this would help. Send an e-mail to your boss asking for clarification that your working hours are 8.30 - 4.30. Keep a copy of any affirmative response.

No, it just means its the norm - the hours that are usually worked by most people. If you've agreed otherwise I wouldn't worry about it!

Typically 9 -5 means that most folks will be working 9 - 5 or something very similar. Your verbal agreement will stand, but be flexible. If they need you to work 9 - 5 for a few days for a special project or something, do it. Most employers want you for 8 hours but won't pay for a lunch hour, so a typical day is 8 - 5!

Yes, it mean the employer can make you work any hours. Typical means normal, but that doesnt mean the employer cant change it.

You can work 9 to 5 (or similiar hours), but there will be occasions when you have to come in extra early or stay extra late.

One of my previous jobs was supposed to be 9 to 5 Monday - Friday, but in fact I was working 7.30 to 6.30 Monday to Friday AND the occasional Saturday as well.

it all depends what is stated in a contract. However if you have been carrying out the verbal agreement for some time. Legally the employer will not be able to change our hours as you have done them for such a long time.