also: どくじゃ
noun
venomous snake; poisonous snake
Refers to any snake that injects venom. In everyday Japanese, 毒蛇 is the general term, though 毒ヘビ is also seen.
この森には毒蛇がいるから気をつけて。
Be careful because there are venomous snakes in this forest.
毒蛇に噛まれたらすぐに病院へ行ってください。
If you are bitten by a venomous snake, go to the hospital immediately.
蛇 is the general word for 'snake', while 毒蛇 specifically means a venomous or poisonous snake.
Compound of 毒 (doku, 'poison') and 蛇 (hebi/ja, 'snake'). The reading どくへび is a straightforward kun'yomi compound, while どくじゃ uses the on'yomi for 蛇.