1. A sloping or bending downward.
2. A falling off, especially from prosperity or vigor; a decline.
3. A deviation, as from a specific direction or standard.
4. A refusal to accept.
5. See magnetic declination.
6. Astronomy The angular distance to a point on a celestial object, measured north (in positive degrees) or south (in negative degrees) from the celestial equator.
[Middle English declinacioun, from Old French declination, from Latin dēclīnātiō, dēclīnātiōn-, from dēclīnātus, past participle of dēclīnāre, to turn away; see DECLINE.]
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Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.