I’ve been told by people with a better eye for flowers than me that this is likely a variant of Elderberry, probably Sambucus canadensis.

Elderberry, Sambucus canadensis (August 20th, 2019, Portugal Cove, NL.)

My honey bees seem to like it, though I didn’t get a photo of a honey bee on it in this series of photos.

I’ve added it to my Newfoundland Honey Bee Forage list even though it’s not a native species of the island.