declination

UK: /ˌdɛklɪˈneɪʃən/ US: (dek′lə nā′shən)

WordReference Random House Unabridged Dictionary of American English © 2025

dec•li•na•tion  (dek′lə nā′shən), n. 

1. a bending, sloping, or moving downward.
2. deterioration;
   decline.
3. a swerving or deviating, as from a standard.
4. a polite refusal.
5. Astronomy the angular distance of a heavenly body from the celestial equator, measured on the great circle passing through the celestial pole and the body.
6. variation (def. 8).
7. the formal refusal by a nominee of a nomination to public office.

• Latin dēclīnātiōn- (stem of dēclīnātiō), equivalent. to dēclīnāt(us), literally, turned aside (past participle of dēclīnāre; see decline, -ate¹) + -iōn- -ion
• Old French declinacion
• Middle English declinacioun 1350–1400

dec′li•na′tion•al, adj. 

Collins Concise English Dictionary © HarperCollins Publishers::

declination / ˌdɛklɪˈneɪʃən/ noun

1. the angular distance, esp in degrees, of a star, planet, etc, from the celestial equator measured north (positive) or south (negative) along the great circle passing through the celestial poles and the body
   Symbol: δ
2. See magnetic declination
3. a refusal, esp a courteous or formal one

ˌdecliˈnational adjective