Androscoggin, Or Ameriscoggin, a river of New Hampshire and Maine. It is formed in Coos county, N.

II., near the Maine boundary, by the union of the Margalloway river with the outlet of Umbagog lake, flows S. to the White mountains, and making a sharp bend to the E. about lat. 44° 20', enters the state of Maine, and joins the Kennebec river at Merry Meeting bay. about 18 m. above the entrance of that river into the ocean. Its length is 157 m., 66 of which are in New Hampshire.