if something is richly decorated, it is decorated a lot, in a way that is beautiful:
a richly carved ceiling
a cloak richly embroidered with gold thread
if someone is richly dressed, they are dressed in expensive clothes
having beautiful strong colours:
the richly coloured mosaic
having a strong pleasant taste or smell:
richly scented flowers
to completely deserve something such as success or punishment:
They got the punishment they so richly deserved.
containing large amounts of something:
a richly wooded valley
an area that is richly endowed with wildlife
giving you a strong feeling of pleasure:
It was a richly rewarding relationship.