Definition of unpickable in English:

unpickable

adjective

  • That cannot be picked; specifically (of a lock) unopenable with an instrument other than the proper key.

Origin

Early 17th century; earliest use found in Francis Beaumont (1584–1616), playwright. From un- + pick + -able.

Pronunciation

unpickable

/(ˌ)ʌnˈpɪkəbl/