| 1 | English | isotope | Any of two or more forms of an element where the... |
| 2 | English | iso- | equal; forms terms relating to isomers; forms... |
| 3 | Ancient Greek | ῐ̓́σος | equal |
| 4 | Ancient Greek | βάρος | weight, burden, load; grief, sorrow; plenty |
| 5 | Ancient Greek | βαρύς | heavy, weighty; heavy, burdensome, oppressive;... |
| 6 | Proto-Hellenic | gʷarus | heavy |
| 7 | Proto-Indo-European | gʷréh₂us | heavy |
| 8 | Proto-Indo-European | -us | Forms adjectives from Caland system roots |