Well, you most likely knew what a rooster is. But, do you know the word "roost"? I must admit that I didn't know it until I looked up Wiktionary.org, which has these for one etymology of this word:
Noun
roost (plural roosts)
- 1. The place where a bird sleeps (usually its nest or a branch).
- 2. A group of birds roosting together.
Verb
- 1. ( of birds) sleep.
- 2. to come back home
There are another two etymologies of roost documented in Wiktionary.org, but I won't bug you with those :)
S.D
2015.1.14