the word of the kingdom

"the message about God's rule as king"

the evil one comes and snatches away what has been sown in his heart

"The evil one causes him to forget the message that he has heard just as a bird snatches away seed from the ground"

This refers to Satan.

Try to use a word that means to grab something away from someone who is the rightful owner.

"the message that God sowed in his heart" or "the message that he heard"

Here "heart" refers to the mind of the hearer.

"This is the meaning of the seed that was sown beside the road" or "The road where seed was sown represents this person"