importantly

The word “importantly” means used to highlight a point as especially significant. In plain terms, used to flag the most significant point in a sentence.

“Importantly” is pronounced ihm-PAW-tuhnt-lee (/ɪmˈpɔɹ.tənt.li/ in IPA).

Here is “importantly” used in a sentence: “More importantly, the results were reproducible across every trial.”

“Importantly” is an adverb.

“Importantly” is a fairly common word in modern English, usually learned at around the A2 level.

“Importantly” has 2 distinct senses listed in this dictionary. The most common is: used to highlight a point as especially significant.

Both are widely accepted at the start of a sentence: 'More importantly, the data was verified' and 'More important, the data was verified'. Some traditional style guides prefer 'more important', treating it as short for 'what is more important', but 'more importantly' is now the more common form and is considered standard. Choose one and use it consistently.

Yes. Used at the start of a sentence, importantly acts as a sentence adverb that flags the point as especially significant, and it is normally followed by a comma: 'Importantly, the results were repeated.' It most often appears reinforced as 'more importantly' or 'most importantly'.

Yes — when 'most importantly' introduces a sentence, standard punctuation places a comma after it: 'Most importantly, back up your files.' The comma marks the phrase off as a comment on the whole sentence rather than part of the clause itself.

As sentence adverbs, both highlight a point and are often interchangeable: 'Importantly, no side effects were reported.' However, significantly also means 'by a large amount', as in 'sales rose significantly', a use importantly does not share. Importantly can additionally describe a self-important manner, as in 'he strode about importantly'.