PIE base ‘track, furrow’.
Other derivatives are lore ‘knowledge passed from generation to generation by oral tradition’, a last ‘form shaped like a human foot’, as a footprint, to last ‘to hold out, endure, continue, follow a track’, and delirium, from Latin delirium ‘to be deranged’, for leaving the track.
[Pokorny *leis- p. 671.]