There do not seem to be any sutiable synonyms except "planting" (for burying).
Perhaps the synonym sought was for internment, which could include prison.
plans
people
The silent letter in "mnemonic" is the "m" at the beginning of the word. In "pneumonia," the silent letter is the "p" at the beginning of the word.
Particle.
Another word for holy is pious.
prow
peripheral
poignant
presume
props
puce
prattle