1. Happening or being undertaken at a fast pace or with a lot of vigor and enthusiasm. Primarily heard in UK. If you're not coming home for Christmas, you need to tell Mom because her planning is already in full flood. Campaigns for both sides are now in full flood ahead of the May election.

2. Engaging in or characteristic of a manner of speaking that is fluent, quick, and/or lengthy. Primarily heard in UK. After a couple of drinks during dinner, my uncle was in full flood about his position on immigration.