What does 20 mean in slang?
What's your 20? is CB (Citizens Band radio) lingo for “What's your location?” What's your 2020 can be part of a question about a person's presidential aspirations for the 2020 election or about a person or organization's goals or aims for the year 2020. (How'd those plans turn out?)
What is Dickweed plant?
While it would be a truly fabulous name for a plant, there aren't any living things called “dickweeds” save for the ones reading this article right now — but it is a colloquial name for a type of algae-bacteria that can cause seaweed dermatitis.
What you mean by duckweed?
Definition of duckweed : a small floating aquatic monocotyledonous plant (family Lemnaceae, the duckweed family)