say it: sti-myuh-LAY-shuhn
stimulation is a noun meaning "the act of arousing an organism to action". It carries 4 recorded senses.
the act of arousing an organism to action
(physiology) the effect of a stimulus (on nerves or organs etc.)
physiology
mutual sexual fondling prior to sexual intercourse
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 stimulation 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.