From Middle English sightlye, equivalent to .

sightly (comparative sightlier, superlative sightliest) (archaic)

1. Attractive, pleasing to the eye; affording gratification to the sense of sight; aesthetically pleasing.
   • 1692, Roger L'Estrange, “ (please specify the fable number.) (please specify the name of the fable.)”, in Fables, of Æsop and Other Eminent Mythologists: […], London: […] R[ichard] Sare, […], →OCLC ↗:

     Many brave, sightly horses.

2. Offering a good view.
3. Open to sight; conspicuous.

• unsightly

• Italian: leggiadro
• Russian: привлека́тельный

• Italian: panoramico
• Russian: ви́дный