If you walk into an air-conditioned room, or taste iced water on a hot day, you might say Ah, what a mechayeh, meaning literally, something that has brought you back from death to life, and colloquially, something relieving or refreshing.
(One could think that the phrase reflects our penchant for dramatic self-expression, where others might simply say, that was nice.)
Mechayeh derives from the Hebrew, chai, meaning life (as in lchaim). In Yiddish, the word has numerous other uses. Something delicious, delightful or enjoyable is mechayehdik. If its extra delicious, you could say its mechayeh nefashos (reviving souls) or mechayeh nefashosdik.
A michyah is a livelihood, something that literally, not metaphorically, sustains you.
In Jewish tradition techiyat hametim is the belief that there will eventually be a resurrection of the dead, codified by Maimonides (1135-1204) as the last of his Thirteen Principles of Faith. (I was moved to use this phrase frivolously this week when my laptop was, seemingly miraculously, mended.)
That we pray for techiyat hametim in the second blessing of the Amidah testifies to the importance of this hope in Judaism. Its striking how such a theological principle has worked its way into everyday Jewish speech.