noun, used as a prefix
prime-
Used as a prefix in loanword compounds to mean 'first', 'best', or 'primary', e.g., プライムタイム (prime time), プライムレート (prime rate).
プライムタイムに放送される番組は視聴率が高い。
Programs broadcast during prime time have high ratings.
プライムレートが上がると、住宅ローンの金利も上がる。
When the prime rate goes up, mortgage interest rates also rise.
noun
prime symbol (')
Refers to the typographical symbol (') used in mathematics, measurements, or as a diacritic; not a common standalone noun in everyday Japanese.
数学で、プライムは微分を表す記号として使われる。
In mathematics, the prime symbol is used to denote differentiation.