This is the 91st most frequent Estonian word.
keegi
"Keegi" means "someone" or "anyone" in English.
In this sentence, 'keegi' is used as an indefinite pronoun to mean 'someone'.
Keegi koputas uksele.
Someone knocked on the door.
In this case, 'keegi' is used with a negation, which changes its meaning to 'nobody'.
Keegi ei tulnud minu sünnipäevale.
Nobody came to my birthday.
Here, 'keegi' is used to indicate an uncertain subject, someone unknown or unspecified.