Origin/meaning of the surname "Twerdoclib"

When working with stuffing envelopes, I came across someone with the last name “Twerdoclib.” I’m wondering what the meaning and/or origin of this name is. I looked it up on Google, and I only turned up results with other people with that same last name (often spelled “Twerdochlib.”)

So, what’s the meaning and/or origin of the name “Twerdoclib/Twerdochlib”?

It’s pronounced Throat-Wobbler Mangrove.

Ukraine. Hard bread.

Thanks!

Has it been transliterated via German? I’m thinking “Tverdotslib” might be a better English rendering.