Sanskrit, pronounced "Nah-mah-skar".
It is usually said with an accompanying action - holding the palms of the hand flat together and touching the thumbs first to the "third eye" area between the eyebrows and then touching the thumbs to the heart.
It means "With all the depths and charms of my mind and all the love and cordiality of my heart, the divinity within me greets the divinity within you". This meaning is the ideation kept in mind when givning the greeting.
Related to namaste, which is often used in the same way, but which was originally intended as a respectful greeting to God alone. Namaskar, on the other hand, is always used as a greeting to other people - eiher friends or strangers.
Street version: skar.