Description:

The term 'stif' refers to shadows and shade. Based on an aold idiomatic American usage that carried through to Common, it is also a word for disparagement or insult, but the implication is a subtle insult that attacks someone's status rather than a blatant one.

Noun:

As a noun 'stif' means a literal shadow or can refer to an insult. The derived form 'stifca' is used as a word for a parasol or other device or structure designed to create shade and generally doesn't carry the negative connotation from the other meaning of stif.

Verb:

As a verb, 'stif' is a transitive skurun verb which takes an ergative subject that casts shade and an absolutive thing shaded. In the sense of insulting someone, the subject is the insulter and the object is the person insulted.

Modifier:

The modifier form 'stifys' meaning 'shady' can means directly simply that its referent is in the shade, but it also has a secondary meaning also calqued from American English of being dishonest or having criminal associations or otherwise not being completely above-board. Another meaning os 'stifys' could be to have a quality of casting shade, or to be insulting and mean.