transitive verb

1. to make light or bright; illuminate
2. to make light or pale
3. to cause to flash in or as in lightning: with out or forth
4. Archaic to give knowledge to; enlighten

Etymology: ME lightnen

intransitive verb

1. to become light; grow brighter
2. to shine brightly; flash
3. to give off flashes of lightning

transitive verb

1. 1. to make lighter in weight
   2. to make less heavy; reduce the load of
2. to make less severe, harsh, or troublesome
3. to make more cheerful; gladden

Etymology: ME lihtnen

intransitive verb

1. to become lighter in weight
2. to become more cheerful