A locking together or interlocking. Also: a crowded mass (of things, esp. vehicles); a jam.

Something inconceivable or unintelligible.

plural. Inscrutable things.

An incomprehensible thing or being (in sense A. 1 or A. 2a).

A thing or quality that cannot be conceived.

the unknown, unintelligible, or inexpressible (cf. je ne sais quoi, n.).

An unknowable thing. Usually in plural.

n. An unsearchable thing.

An indefinable person or thing.

figurative or in figurative context; also with up. a sealed book: often used predicatively of something involved in obscurity, or beyond a…

With the. That which cannot be known.

n. An unintelligible thing.

An instance of this; something that is inconceivable.

An imponderable substance or agent. Now chiefly figurative in sense ‘something that cannot be estimated’.

An instance of this; something inscrutable.

(un-, prefix1 affix 6; cf. unfathomable, adj.)

That which cannot be conceived or imagined.

something unknown or uncomprehended (cf. open book, n.).

Anything intangible; spec. (in plural) = intangible assets, i.e. assets (e.g. goodwill, rights, etc.) which cannot easily or precisely be measured.

With plural agreement. Imponderables, imponderable factors.

a difference of attitudes and values between people of different generations, esp. parents and children, leading to a lack of understanding; cf. gap…