Adjective

(er)

Hard to grasp; not obvious or easily understood; barely noticeable.

The difference is subtle , but you can hear it if you listen carefully.

(of a thing) Cleverly contrived.

(of a person or animal) Cunning, skillful.

insidious

* 1623 , , act iv, scene 4,

Thy age confirmed, proud, subtle , bloody, treacherous.

Tenuous; rarefied; of low density or thin consistency.

Adjective

(er)

Untrue, not factual, factually incorrect.

*{{quote-book, year=1551, year_published=1888

, title= A New English Dictionary on Historical Principles: Founded Mainly on the Materials Collected by the Philological Society , section=Part 1, publisher=Clarendon Press, location=Oxford, editor= , volume=1, page=217 , passage=Also the rule of false position, with dyuers examples not onely vulgar, but some appertaynyng to the rule of Algeber.}}

Based on factually incorrect premises: false legislation

Spurious, artificial.

:

*

*:At her invitation he outlined for her the succeeding chapters with terse military accuracy?; and what she liked best and best understood was avoidance of that false modesty which condescends, turning technicality into pabulum.

(lb) Of a state in Boolean logic that indicates a negative result.

Uttering falsehood; dishonest or deceitful.

:

Not faithful or loyal, as to obligations, allegiance, vows, etc.; untrue; treacherous.

:

*(John Milton) (1608-1674)

*:I to myself was false , ere thou to me.

Not well founded; not firm or trustworthy; erroneous.

:

*(Edmund Spenser) (c.1552–1599)

*:whose false foundation waves have swept away

Not essential or permanent, as parts of a structure which are temporary or supplemental.

(lb) Out of tune.