say it: SIL-uhn-dur
cylinder is a noun meaning "a solid bounded by a cylindrical surface and two parallel planes (the bases)". It carries 4 recorded senses.
a surface generated by rotating a parallel line around a fixed line
a chamber within which piston moves
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 cylinder 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.