leis- / Indo-European roots
1. O-grade form *lois-.
a. last3 from Old English lāst, lǣst, sole, footprint, from Germanic *laist-;
b. last2 from Old English lǣstan, to continue, from Germanic *laistjan, "to follow a track";
c. suffixed form *lois-ā-. lore1 from Old English lār, learning, from Germanic *laizō.
2. learn from Old English leornian, to learn, from Germanic zero-grade form *liznōn, "to follow a course (of study)"
3. Suffixed full-grade form *leis-ā-. delirium from Latin līra, a furrow.
[Pokorny leis- 671.]
Small.least, less from Old English comparative lǣs, lǣssa and superlative lǣst, lǣrest, from Germanic comparative *lais-izō and superlative *lais-ista-.
[In Pokorny 2. lei- 661.]