| 1 | English | Brook | — |
| 2 | Dutch | broek | pair of trousers, pair of pants; pair of... |
| 3 | Middle Dutch | broec | trousers, pants, breeches; low land, wetland,... |
| 4 | Old Dutch | bruoc | trousers, pants, breeches; wetland, marsh |
| 5 | Proto-Germanic | brōks | rear end, rump, hindquarters; leggings, pants,... |
| 6 | Proto-Germanic | brāks | — |
| 7 | Proto-Indo-European | bʰrāg- | rump, hock, hindquarters |
| 8 | Proto-Indo-European | bʰrēǵ- | to shine, shimmer |