IPA: /ˈsaɪt.lɪ.nəs/
KK: /ˈsaɪtli/
The quality of being attractive or pleasant to look at.
The sightliness of the garden impressed all the visitors.
Sightliness → It is formed from "sight" (from Old English *sīht*, meaning the ability to see) and "-liness" (from Old English *-licness*, meaning the quality of being). The word "sightliness" refers to the quality of being pleasing to the eye or visually attractive.
Think of the ability to 'see' ('sight') and the quality of being pleasing ('-liness') — this helps you remember that sightliness means being visually attractive.