I came up with this sentence while reading manga:
Context: That's what the grandfather says after his grandson exits the house without telling anyone.
育って - I believe it's the te-form of the verb 育つ, which means (from Jisho.org):
- to be raised (e.g. child); to be brought up; to grow (up)
I don't know what "しもーたん" is. But from my research I gathered that しも could be a grammatical element in archaic Japanese (a sort of intensifier similar to nothing but, even, necessarily, etc) and looking at Jisho.org, たん could be an honorifc but that doesn't make sense since there is no character called しも.
My second guess is that しもーたん could be a contraction for something else, which I cannot guess.