"lest you lose" is a correct and usable phrase in written English.
It is used to suggest a possible negative outcome, and is used especially when someone is being warned. For example, "Careful with that precious vase, lest you lose it!".
Lest you lose yourself and then.
So try to avoid peeling foods like apples, peaches and eggplant lest you lose their most concentrated source of beneficial chemicals.
After you make that one product compromise to satisfy some crazy customer, then you've got to support that setting forever lest you lose the customer who depends on it.
And as for you, Mr. Maciques, I certainly hope male pattern baldness doesn't accost you later in life, lest you lose any self-worth along with your luscious locks.
Capturing your thoughts quickly is vital to being a philosopher and writer, lest you lose it.
Frequently question your own understanding of microgravity, lest you lose track of its true meaning.
On Monday, Hamilton -- who, lest you forget, lost her left arm to a shark when she was 13 years old -- surfed some of the biggest, most dangerous waves of her life.
I can't get too carried away, lest I lose my friends, but that gets increasingly hard when you've had a few and the DJ starts dropping red hot bangers.
Silliness, lest you thought it was lost altogether, all but defines "Betwixt!" — the loopy musical that was once called "Enchanted" and that has extended its run at the 98-seat Trafalgar Studios 2, even as its American star, Ellen Greene, left the production this weekend to return home.
But lest you think he's losing his elasticity, he rebuffed my suggestion that age was a factor.
But I'm just not sure that people would remember the whole stage-diving thing, and I might hit [the ground]." But lest you think he's losing his elasticity, he rebuffed my suggestion that age was a factor.
