Every used club gets a number from 6 to 9.5. Here's exactly what each one means, so you can trust a 7 as much as a 9.
9.5Mint
Hit a handful of times at most. No marks worth mentioning. Original grip like new. Basically a demo.
9Excellent
Light use — a few rounds. Faint bag chatter only under close inspection. Grooves sharp. Grip near new.
8Very good
Normal play wear from a season or so. Sole scuffs, maybe a faint crown mark. No dents, no rattles, no sky marks worth a photo. Grip good.
7Good
Honest wear. Visible sole and face scratches, a sky mark or two on the crown, some paint wear. Grip may be worn (we say so). Plays perfectly.
6Fair
Well-used. Cosmetic issues we photograph and describe individually. Priced accordingly — these are usually the best value on the rack for someone who doesn't care about looks.
What isn't graded — it's rejected
Cracked or caved faces, rattles, bent hosels, stripped adapters, counterfeits, anything with a repair we can't verify. These get destroyed or returned, not resold.
Every listing also tells you
Grip condition (New / Good / Fair / Worn). Exact shaft, flex and length. Loft, and lie if it's been altered from stock. Whether the headcover and wrench are included. Serial number if it matters for the model. And a note from whoever graded it — "small sky mark near heel, otherwise clean" kind of thing.
Photos
Face, sole, crown/topline, grip, and shaft band — of the exact club with that SKU. Not a stock image, not "representative."