Words that come from Proto-Indo-European denḱ-

97 words across 33 languages descend from Proto-Indo-European denḱ- — including thou, tough, tong, toughen, toughie, toughminded, toughish, tonging.

See the etymology of denḱ- itself →

English (22)

Dutch (7)

German (7)

Proto-Germanic (5)

Icelandic (4)

Ancient Greek (4)

Middle English (4)

Sanskrit (3)

Albanian (3)

Old Dutch (3)

Swedish (3)

Translingual (3)

Old English (3)

Middle Dutch (2)

Old Norse (2)

Norwegian Bokmål (2)

Norwegian Nynorsk (2)

Old High German (2)

Proto-Indo-Iranian (2)

Danish (1)

Faroese (1)

Luxembourgish (1)

Japanese (1)

Konkani (1)

Ido (1)

Hindi (1)

Sauraseni Prakrit (1)

Saterland Frisian (1)

Proto-Indo-Aryan (1)

Proto-Indo-European (1)

Old Frisian (1)

Middle High German (1)

Proto-Albanian (1)