There are 1,218 12-letter words that end with 'ing'.
Note: These 1,218 12-letter words that end with 'ing' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words end with ting, ling, ring, ning, sing, zing, ding, king, ying, hing, ging, ping, ming, cing, wing, ving, bing, fing, eing, oing, uing, xing, aing, iing.
4-letter words end with 'ing' (9)