This is the 6419th most frequent Russian word.
штрафом
"Штрафом" means "with a fine" in English.
Here, "штрафом" refers to the means of fulfilling an obligation.
Заплатить штрафом нужно в течение месяца.
The penalty should be paid within a month.
The word "штрафом" is used to specify the punishment imposed.
За нарушение правил оштрафовали с внушительным штрафом.
For rule violation, they fined with a significant penalty.
"штрафом" indicates the association with a penalty that accompanies the described violations.