Meaning

adjective not having or covered with a lid or lids

adjective having no lid

adjective always watchful; - Alfred Tennyson

originEtymology tree English lid Proto-Indo-European *lewh₁- Proto-Indo-European *lewHs-der. Proto-Germanic *leusaną Proto-Germanic *lausaz Proto-Germanic *-lausaz Proto-West Germanic *-laus Old English -lēas Middle English -les English -less English lidless From lid + -less.

Etymology from Wiktionary, CC BY-SA 3.0