This is the 12121st most frequent Russian word.
изобретений
"Inventions."
The word 'изобретений' is used in the genitive plural form to denote 'of inventions,' indicating possession or a category being discussed.
Он увлекается чтением книг о величайших изобретениях человечества.
He enjoys reading books about the greatest inventions of humanity.
The word 'изобретений' appears in this case to indicate creative engineering outputs, used in a possessive or descriptive context.
Выставка представила несколько новых изобретений молодых инженеров.
The exhibition showcased several new inventions by young engineers.
Here, 'изобретений' refers to the plural concept of innovations or creations generally, fitting in the construct showing indirect action toward or regarding them.