This is the 12418th most frequent Russian word.
кашлем
"Кашлем" means "cough" (as in the act of coughing).
The word 'кашляет' is used as a verb in the present tense to indicate the act of coughing.
Мы попросили его отходить от стола, когда он кашляет.
We asked him to step away from the table when he coughs.
The word 'кашель' is used as a noun to describe the condition or symptom of coughing.
У него сильный кашель, и он плохо себя чувствует.
He has a strong cough and he feels unwell.
The word 'кашля' appears in a noun form modified by a preposition in a genitive case, indicating possession or connection to the cough.