please what does a locked icloud imply on an iphone?

Does your screen look like this (with the ID being shown not yours)? -

This is 'Activation Lock', and anti-theft device intended to make a stolen iPhone useless to the thief. It appears when the phone is reset or upgraded. Did you buy the phone second-hand (used)?

If a second-hand iOS device has been 'Activation locked' then only the previous owner can unlock it, either by providing you with the account ID and password, or by removing it from his list of devices (as he should have done before selling it) - please see http://support.apple.com/kb/ts4515

If you are unable to contact him to do this then I'm afraid you will not be able to use the device - there is no other way of unlocking it at all. Apple cannot unlock it for you.

You should if possible return it to wherever you bought it and ask for a refund as in this event the device is completely useless.