The school is considering allowing older students to leave the campus for lunch on Fridays, but I'm concerned that 'if we give them an inch, they'll take a mile'. [=students will leave campus more often]
I begged him to reconsider, but he wouldn't 'give/budge an inch'. [=he wouldn't make even a slight change in his opinion or attitude]
I tried to improve the system, but she opposed me 'every inch of the way'. [=she opposed everything that I tried to do]
(..) Who? I need to ask you a few questions. Anything, m'boy. Anything! Would you mind identifying this wand? We need to know if it's safe to use. Uhh... Walnut Dragon Heartstring and three quarter inches. Unyie... Unyielding. This belonged to Bellatrix Lestrange. And this? Hawthorn. An unicorn hair. inches. Reasonably pliant. This was the wand of Draco Malfoy. Was? Is it not still? Well, perhaps not. If you won it from him. I sense its allegiance has changed. You talk about wands, as if they have feelings... (..)2011 Harry Potter and the Deathly Hallows: Part 2