Hello, I am here to ask if there are any historians here that could answer me. Is it possible that you would tell me where my surname originates from or at least what the meaning is (my surname is Strbad)? Thank you in advance! You are doing a great job!

After some consultation with a Croatian friend, it appears to derive from an archaic word in Bosnian-Croatian-Serbian (BCS) štrb 'one who is lame', plus an old plural marker.

Edit: For the life of my I can't figure out how to directly link to the entry, but if you search for the word in this dictionary you'll find the entry

zast. krnj, kljast, nepotpun

'arch. truncated, lame, incomplete'

The plural suffix -ad is found in other words like telad 'calves'. I suspect it's related to the -jata ending you see in Russian words like teljata 'calves', but it's hard to say, since I don't know the details of the history of BCS, and the -jata suffix is of pretty obscure origin anyways.