There are 14 15-letter words that end with 'ingly'.
Note: These 14 15-letter words that end with 'ingly' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words end with tingly, ringly, lingly, dingly, ningly, hingly, singly, kingly, pingly, gingly, yingly, mingly, vingly, zingly, cingly, bingly, wingly, uingly, xingly, oingly, jingly.
6-letter words end with 'ingly' (4)