IPA: /ˈɡlæsiəst/
KK: /ˈɡlæs.i.ɪst/
Having the most glass-like quality, often referring to a shiny, smooth, or reflective surface.
The lake was the glassiest I had ever seen, perfectly reflecting the sky above.
Comparative: glossier
Superlative: glassiest
Glassiest → It is formed from "glass" (from Old English *glæs*, meaning a transparent substance) and "-iest" (a superlative suffix indicating the highest degree). The word "glassiest" means having the highest degree of glass-like qualities, such as being very shiny or reflective.
Think of the word 'glass' which refers to a shiny, transparent material, and remember that 'glassiest' means the most glass-like or shiny.