| 1 | Old English | bēam | tree, cross, gallows, column, pillar, wood, beam,... |
| 2 | Proto-West Germanic | baum | tree; beam |
| 3 | Proto-Germanic | baumaz | Alternative form of *bagmaz; tree, beam, balk;... |
| 4 | Proto-Indo-European | bʰew- | to grow, swell; to swell, wax, grow; to blow; to... |