Open lipped or open lip?

[Ruifeng]

An open lipped kiss or an open lip kiss?

A red hair girl or a red haired girl?

thanks

[Beeesneees]

'Open lipped'. and 'red haired'

Lips come in pairs. A single lip cannot open.
A red hair girl sounds like a girl formed entirely from red hair.
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Cheers m' dears!

[Clubmember]

Yes, open lipped and red haired are working as an adjective (adjectives comprising more than one word are compound adjectives). Possible combinations for compound adjectives include

Adj / Adv / N + past participle
Adj / Adv / N + present participle

Adj / Prep + N
Adj + N + ed

N / Adj + adj

In open-minded, open is an adjective and minded is a past participle.
In red-haired, red is an adjective and haired is N+ed.

Although it is possible to form compound adjectives using Adj + N combination, they are not appropriate for the reasons given by Beeesneees.

* Please correct me if I am wrong.