Without grubs; free from grubs or larval insects, or lacking a grubstake.
From 'grub' (noun) + '-less' (suffix meaning without, from Old English -leas). The -less suffix freely attaches to nouns to create adjectives meaning the absence of that thing.
The -less suffix is so productive that we instantly understand 'grubless' means 'without grubs,' but it's poetic that this word captures the absence of something so small and insignificant!
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