Hangul syllable gwiss

It spells one syllable; its word supplies the meaning.

Hangul's smaller consonant and vowel letters are called jamo; they build square syllable blocks. The Unicode decomposition of 귔 is initial ᄀ, vowel ᅱ, and final ᆻ. On a Korean keyboard, these are entered as ㄱ, ㅟ, and ㅆ.

Hangul was devised under King Sejong in 1443. At the time, writing Korean relied heavily on Chinese characters that did not fit its sounds well, so Hangul offered a simpler alphabet for Korean speech. The 1446 guide 훈민정음 explains the system's purpose and design.

How do I type 귔?

Use a Korean 2-set keyboard and enter the parts in order.

On Dubeolsik, type r for ㄱ, n then l for ㅟ, and Shift+T for ㅆ; the input method joins them into 귔. Other Korean layouts use different keys for the same parts.

Is “gwiss” how 귔 is pronounced?

Not always; Korean pronunciation depends on what follows.

At the end of a Korean syllable, final ㅆ sounds like a short, unreleased t; before a following vowel, it links into the next syllable as a tense ss. “Gwiss” is the character's English label, not a fixed spoken form.