English word fidelity comes from Proto-Indo-European *bʰidʰ-, and later Latin fidelitas (Faithfulness, fidelity.)
| Dictionary entry | Language | Definition |
|---|---|---|
| *bʰidʰ- | Proto-Indo-European (ine) | to command, pot, bucket, barrel |
| fidere | Latin (lat) | |
| fidem | Latin (lat) | |
| fidelis | Latin (lat) | Faithful, loyal. True, trustworthy, dependable A confidant, trustworthy person. |
| fidelitas | Latin (lat) | Faithfulness, fidelity. |
| fidélité | Middle French (frm) | |
| fidelity | English (en) | Accuracy, or exact correspondence to some given quality or fact.. Faithfulness to one's duties.. Loyalty to one's spouse or partner, including abstention from extramarital affairs (except in an open marriage).. The degree to which a system accurately reproduces an input. |