(Diary of a Teetotaling Linguist)
You are absolutely right to cling to the word nip like a drowning man to a straw. But translating this deeply spiritual Slavic cultural phenomenon into English goes completely sideways, all because your Western bar systems chop up reality in utterly nonsensical ways!
Nip (a.k.a. "The Lil' Bite"): Historically, it’s just a teeny-tiny sip (from some funny old word nipperkin). Nowadays, in US slang, it's a pocket-sized bottle of hard liquor. But here’s the catch: Americans think a nip is a microscopic 50ml souvenir shot, which we proudly call a merzavchik (literally "the little scoundrel")!
A Tragedy in One Act (to be read while holding the skull of a "little scoundrel"):
To Nip, or not to Nip? That is the question.
Whether 'tis nobler in the Slavic soul to suffer
The slings and arrows of a mere fifty milliliters,
Or to take arms against a sea of dictionaries,
And by opposing, find a bigger volume? To sleep, perchance to dream...
Of a faceted glass! Ay, there's the rub:
For in that souvenir packaging, no truth can hide,
And what we need, my lords, is a Chekushka!
Half-pint (Mathematically Challenged): In the US, the closest relative to our chekushka is the 200ml flask. The people stubbornly dub it a half-pint, completely ignoring the fact that it's mathematically short of an actual half-pint! But this is exactly the size you stuff into a crinkly brown paper bag to "relieve stress" and warm up on your way home.
Quarter-bottle (With a Monocle): Stiff-upper-lip Brits adore this term, meaning a quarter of a standard bottle. Etymologically, it’s the identical twin of our chekushka, which was born from chetvertushka (a quarter of a shtof — an ancient Russian liquid measure).
The Final Verdict:
If we want to nail the vibe in a novel, nip or a half-pint of vodka are our best buddies. But no dictionary will ever convey the main drama! Out in the West, a nip is chugged sadly and in solitude, hiding from the cold and harsh reality. But our native chekushka is practically a portal to other dimensions, a bridge between humans, and the liquid equivalent of the ultimate question: "Do you feel me, bro?".
P.S. Darn it, look at this majestic ode to alcohol I just penned! And I don't even drink! To top off this absurdity, while completely sober, I managed to screw up: in my book, I accidentally gave the word Nip a masculine gender in Russian. Talk about taking your eye off the ball...