1) General subject: adder, grass-snake, indeed, well, would + verb (He would know! - Он-то уж знает!)
2) Biology: (настоящий) common water snake (Natrix), water snake (Natrix)
3) Mathematics: to be sure, (emphatic particle) very, (grass) snake
Универсальный русско-английский словарь. Академик.ру. 2011.