Sentence:  At first, when the net was being prepared, those children of the forest had merely stood by and looked on with curiosity. When Blondin and his men rowed out from the shore, letting the net drop off the stern of our boat as they went, they indulged in a few guesses and <WSD>undertoned</WSD> remarks. 
Meaning of the word marked with <WSD> tags:  To say or speak in an undertone.