What's a "right old roarer" in British English?

Solution 1:

If this is the Amazon context you refer to,

The more Tchaikovsky's reputation grew as a composer, the more anxious he became to avoid public disclosure as a homosexual. He was a right old roarer apparently, specialising in boys in their early to mid teens.

it seems quite well-fitting with the slang definition of roarer

a male homosexual, especially one who is actually or supposedly flagrant.

I've not come across this word myself before, so not sure how common this is in BrE.

Without the full context, I thought roarer meant "someone who communicates vocally in a very loud voice"

Solution 2:

From Auden's As I Walked Out One Evening:

…
And the crack in the tea-cup opens
A lane to the land of the dead.

Where the beggars raffle the banknotes
And the Giant is enchanting to Jack,
And the Lily-white Boy is a Roarer,
And Jill goes down on her back
…