This is the 568th most frequent Czech word.
jím
"I eat."
The word 'jím' is the first-person singular present tense of the verb 'jíst' (to eat), indicating the subject is currently performing the action of eating.
Jím jablko každý den.
I eat an apple every day.
Here, 'jím' is the instrumental form of 'on' (he/it), used in conjunction with 'tím' to provide a means or manner context.
Nevím, co tím jím sleduje.
I don't know what he means by it.
In this sentence, 'jím' is the instrumental form of the pronoun 'on' (he), marking the object of the preposition 's' (with).