Like half the universe I'm reading Eat, Pray, Love, and enjoying the author's exuberant love affair with the Italian language. She declares her favorite word to be attraversiamo, "cross over to the other side," which rolls seductively off the tongue (and also happens to summarize her life story). My first favorite word in Hebrew, long before I knew what it meant, was oz (strength). I heard it every week as part of the blessing at the end of the Friday night service, but didn't care what it meant--just that it buzzed and lingered when I said it, as if the joy of the evening was trying to stick inside my mouth like taffy.
My current favorite word is from the Shema: m'odekha. It's usually translated as "might," as in the original Ugaritic, a pre-Biblical language. But me'od in Hebrew means "much." So m'odekha is, literally, "your muchness," as in
V'ahav'ta eit Adonai Elohekha b'khol l'vav'kha uv'khol naf'sh'kha uv'khol m'odekha.
And you shall love the Lord your God with all your heart and with all your soul and with all your muchness.
I think this is a perfect word to describe a relationship with God. God is not a fellow human, so prosaic emotions like love and hate can't really apply. We need a different language, one of awe and abundance, laughter and tears mixed together until they cease to have meaning, to describe the being together of God and humankind. "Muchness" is on the scale of the ocean and desert, so vast and unexplainable that it bypasses grammar, what you might sputter out if drunk or astonished and all other words fail. It sounds like something a child would say who doesn't yet have command of language, but we understand exactly.