Proto-Indo-European Roots
| Root/Stem: | *k'r.d- |
| Meanings: | heart |
| Cognates (): | |
| Hellenic | Greek kradié, kradia 'heart' |
| Italic | Latin cor, gen. cordis 'heart' |
| Celtic | Common Celtic *krdjo-n > Old Irish cride 'heart', Welsh craidd, Breton kreiz 'middle', Irish croithe, Scottish crithe |
| Indic | Sanskrit hr.d- 'heart' |
| Iranian | Avestan z@r@d 'heard' |
| Anatolian | Hittite kir, kardi- 'heart', Palaic kart-, Lycian kride- |
| Armenian | Armenian sirt 'heart' |
| Germanic | Common Germanic *xirtan > Gothic hairto, Old English heorte, Old Frisian herte, Old Saxon herta, Old High German herza, Old Norse hjarta; Dutch hart, German Herz |
| Baltic | Lithuanian irdis, dial. erdis 'heart', Latvian sirds, Old Prussian seyr 'heart', Sudovian sêras |
| Slavic | Common Slavic *sïrdïce 'heart' > Russian serdtse, Ukrainian & Polish serce, Bulgarian s@rce, Macedonian & Serbo-Croatian & Slovene srce, Czech & Slovak srdce |
| Notes: | A perfect Indo-European root which was preserved fairly well in the majority of dialects. In fact the original root used to be *ker-, and *kr.d- it one of its derivatives shaped by the element *-d-. |