To steep is a verb meaning to soak in liquid, so steeped is the
past tense. Steeped can also be an adjective meaning filled,
saturated, permeated. Here are examples of its use:
"She steeped the herbs for 15 minutes to make her tea."
"They were overwhelmed by the thought that the castle was so
steeped in centuries of history."
"The steeped tea was too strong."