ravine, small valley made by running water.
relent, yield, give in, forgive.
revenge, return of evil for evil.
revive, bring back to life.
rippling, moving up and down or back and forth, like water.
rung, step (of a ladder).
sanctuary, refuge, shelter, place of protection.
serene, quiet, calm.
sibilant, high, piercing, hissing notes.
soot, a fine black powder left by smoke on the inside of chimneys.