say it: pree-SESH-uhn
precession is a noun meaning "the motion of a spinning body (as a top) in which it wobbles so that the axis of rotation sweeps out a cone". It carries 2 recorded senses.
the motion of a spinning body (as a top) in which it wobbles so that the axis of rotation sweeps out a cone
the act of preceding in time or order or rank (as in a ceremony)
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for precession come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.