Lethe
/ˈliːθi/
Definition 1 of 2
Pro Tip 1/3Mythological Origin
Remember that 'lethe' originates from Greek mythology and is often used in literary or historical contexts. 
Poets sometimes reference drinking from the river of lethe as a metaphor for forgetting.
Pro Tip 2/3Literary Symbolism
'Lethe' is symbolically linked to forgetting past troubles or the relief of memory's burdens. 
After her journey, she felt as if she bathed in the river of lethe, unburdened.
Pro Tip 3/3Cultural Associations
Understanding 'lethe' may require familiarity with Western literary and cultural references to Hades and the afterlife. 
His memoir avoided the darker times, a narrative lethe cleansing historical memory.