crypto-dynamic
/ˌkrɪptəʊdʌɪˈnamɪk/adjective
Mechanics. Designating an enclosed two-speed epicyclic gear originally designed for use on bicycles. Compare crypto. Now historical and rare.
- The gear was invented by W. T. Shaw of the Crypto Cycle Company, London..
Origin
Early 19th century (in an earlier sense). From crypto- + dynamic.