Did you know that a small thing like "feather" is an important part of a few idioms in English? No? So read these useful idioms and do not forget to make your own sentences with them in order to learn them more effectively.
a feather in someone's cap
something very good that someone has done
be as light as a feather
if something is as light as a feather, it is very light
feather your own nest
to get money by unfair and dishonest methods
ruffle someone's feathers
it means to annoy or upset someone
birds of a feather
you use it to talk about guys who have similar interests, tastes, etc.