Definition unknown; purpose unknown; how it's calculated, unknown; what federal regulators think it means, unknown.

释义未知；用途未知；如何计算，未知；联邦监管机构认为其意义何在，未知。

youdao

Idiopathic means the cause is unknown.

VOA: special.2010.11.02

This intense heat they project in a parallel beam against any object they choose, by means of a polished parabolic mirror of unknown composition, much as the mirror of a lighthouse projects a beam of light.

VOA: special.2010.09.01

Robert Chalmers, 59, denies murdering Samantha Wright "by means unknown" and hiding her body in a garden bin.

BBC: Samantha Wright murder trial shown CCTV footage

Mr Kane is accused of hitting his gran on the head with a blunt implement, applying pressure to her neck by means unknown and murdering her.

BBC: Kathleen Milward's grandson Garry Kane 'bought heroin'

Prosecution lawyers claim that Mr Conning seized hold of her, locked the front door of the property and prevented her from escaping before striking her by means unknown.

BBC: Man on trial over woman's fall from Dundee high rise