This is the 627th most frequent Greek word.
ουσιαστικά
"Ουσιαστικά" means "nouns" in English.
In this sentence, 'ουσιαστικά' is used as an adverb, meaning 'essentially' or 'effectively', to emphasize the significant impact of her intervention.
Η παρέμβαση της ήταν ουσιαστικά καταλυτική.
Her intervention was essentially catalytic.
Here, 'ουσιαστικά' is a noun and refers to the grammatical category of 'nouns'.
Τα ουσιαστικά στη γραμματική είναι μια βασική κατηγορία λέξεων.
Nouns in grammar are a fundamental category of words.
In this context, 'ουσιαστικά' is used as an adverb meaning 'in essence' to summarize the meaning of what is being said.