This is the 488th most frequent Tamil word.
இவன
"He" or "This person" (referring to a male).
Here, 'இவன்' refers to a male subject who is nearby or directly being referred to in an informal or familiar context.
இவன் என் நண்பன்.
He (this person) is my friend.
In this sentence, 'இவனை' is the accusative case of 'இவன்', indicating 'him' as the object of the action.
இவனை நீ சந்தித்தாயா?
Did you meet him (this person)?
'இவனுக்கு' in this example is the dative case of 'இவன்', meaning 'to him', indicating possession or relation.