Rain, precious rain & quiz

It finally rained Friday night for the first time since April! The sky cloudy and dark burst forth with refreshing rain! Rainy season has begun.
These white and yellow "frangi pani" flowers are so pretty and fragrant too. Thought you would enjoy seeing their beauty.
So I have this word Buka Buka on my mind. Let's see who can guess what this word, a noun, is? No fair anyone who has been to Zambia before. All you'll win is the satisfaction of a correct guess. Fill in the comment section with answers, just for fun.