Drowsy vs Slumbrous - What's the difference?

As adjectives the difference between drowsy and slumbrous

is that drowsy is inclined to drowse; heavy with sleepiness; lethargic; dozy while slumbrous is slumberous.

(er)

Inclined to drowse; heavy with sleepiness; lethargic; dozy.

I was feeling drowsy and so decided to make a cup of coffee to try to wake myself up.

Disposing to sleep; lulling; soporific.

It was a warm, drowsy summer afternoon.

Dull; stupid.

* drowsiness

(en adjective)

slumberous.

*1794, , lines 13-14-15

Night is worn,

And the morn

Rises from the slumbrous mass.

* slumbrously * slumbrousness