This is the 1562nd most frequent Turkish word.
kendisiyle
"With oneself" or "with himself/herself."
The word 'kendisiyle' is used in the context of referring to a third person (he/she) in a formal and respectful manner.
Kendisiyle tanıştığımızda çok heyecanlandım.
When I met him/her, I was very excited.
Here, 'kendisiyle' is used to indicate a suggestion to communicate directly with the person being discussed.
Bu sorunu kendisiyle konuşman gerektiğini düşünüyorum.
I think you should talk to him/her about this issue.
In this sentence, 'kendisiyle' expresses agreement with the perspective or opinion of a third party in a formal tone.