Abysmal vs Atrocious [closed]

I came across these two words today, having previously known the meaning of atrocious but completely baffled as to the meaning of abysmal. However, Cambridge dictionary database suggests that these two are very synonymous and could be used almost interchangeably.

Abysmal is defined as simply 'very bad' whereas atrocious is defined as 'of very bad quality'. https://dictionary.cambridge.org/dictionary/english/atrocious https://dictionary.cambridge.org/dictionary/english/abominable

Therefore, would 'his Russian is atrocious' and 'his Russian is abysmal' same thing?

Can anyone shed some light? Much appreciated

They are indeed very close/almost interchangeable. I would look at the nouns to which they are usually applied here:

• atrocious: crime, act, murder, condition, spelling, grammar.
• abysmal: ignorance, record, performance, poverty, conditions, quality, perplexity, result, and failure

... but I would have a hard time giving a more general/abstract difference of when to use which word. I would have to say that "his Russian is atrocious" seems slightly more idiomatic (note that "spelling" and "grammar" are both on the "atrocious" list, but I don't think "his Russian is abysmal" would strike me as unusual.