deloth
From Tolkien Gateway
delos (also deloth) is a Sindarin word meaning abhorrence, detestation, loathing. Its Middle Sindarin form would be delyoss, delyoθ, while the Old Sindarin would be delegosse, delegotthe. See also fuia- and thaur.
Didier Willis (ed.), Hiswelókë's Sindarin dictionary, Edition 1.9.1 (Lexicon 0.9952)