These related forms share the root ر م ي but perform different grammatical and semantic functions.
Word / formMeaning / explanation
يَرْمِيactive imperfect: he throws.
رَامٍactive participle: one who throws.
مَرْمِيٌّpassive participle: something thrown.
رَمْيٌverbal noun: the act of throwing.
The same radicals can express action in time, the doer, the entity affected, or the abstract act; morphology distinguishes those functions.