offhand, off hand, offhandedly

[Ju]

1. I made a speech offhand.
2. I made a speech off hand.
3. The speech I made was offhand.
4. I made a speech offhandedly.

• Are the above sentences correct?
• Are they all in same conotation?
• Any better vocabuary in common usage can replace offhand?

Thanks

[Anglika]

offhand


• adjective ungraciously nonchalant or cool in manner.
• adverb without previous consideration.



Is this what you understood by "offhand"? Or were you thinking more like "off the cuff" = doing something spontaneously and without preparation?