Definition from Wiktionary, the free dictionary
lastly (not comparable)
- (sequence) Used to mark the beginning of the last in a list of items or propositions.
- Firstly, that's illegal; secondly, it has serious disadvantages; thirdly, it's not necessary; and lastly, did I mention that it's illegal?
- (discourse marker) Used to signal that the speaker is about to yield control of the conversation.
- (last in order): finally, last, last of all
- (discourse marker): finally, to conclude, to sum up, in conclusion; ultimately, in the end, all in all, at last