IPA: /ˈpiːkləs/
KK: /ˈpikləs/
Describing something that does not have a pointed top or summit.
The mountain appeared peakless, with a smooth and rounded shape.
Peakless → It is formed from "peak" (from Old English *pīc*, meaning a pointed top or summit) and "-less" (meaning without). The word "peakless" describes something that does not have a peak or pointed top.
Think of something that is 'without' ('-less') a 'pointed top' ('peak') — that's why peakless means lacking a peak.