They need to raise thousands of dollars for this project, so our 20-dollar donation is just 'a drop in the bucket'.
It's raining 'buckets'. = The rain is coming down 'in buckets'. [=it's raining very hard]
The rain is really 'bucketing down'. = It's 'bucketing down'. [=it's pouring]
(..) Ooh, nice. Gathering toys Formy little boy - Look! Pretty! - Oh! Help! Wh-Wh-Wh-Where's the bucket? Help! Water! Where's the water? Here it is! l got it! Here's water! Here's some water! Help! Where's water? That was close. Maybe we'd better go to bed... before something else happens. (..)1940 Pinocchio