I would say it’s pretty definitive. Gammon is basically cured (like bacon) but uncooked. Ham is the same joint, but cooked. It’s saltiness varies widely, and it can be bought smoked or unsmoked. Just like bacon. Ham can be cold or hot, but either way it’s cooked.
OK, but like many a definition, it has plentiful exceptions; you can buy cooked gammon on the rotisserie/hot counter of supermarkets that have one of those, and you can buy cold, cooked gammon in whole or sliced form, and you can buy a ‘ham joint’ that will require cooking at home.
Even easier is Waffle House if there’s one near you. Two menu staples are city ham and eggs and country ham and eggs, the latter being more expensive. Like you said, it’s chewy – they give you a steak knife to use on it but not for the city ham.
As a kid growing up in Pittsburgh, we always bought deli ham from a chain called Isaly’s. It was specifically chipped-chopped ham. My mom would heat it in some Isaly’s barbecue sauce and serve it on a bun. These were called barbecue ham sandwiches.
As an adult I was surprised to find out it was a local thing.
As a child, and as long as I lived with my dad, 5-pound canned hams were what we ate when we had ham for dinner. Dad would score the top diagonally, and then score it in the opposite direction. He put a whole clove into each intersection, covered the top with orange marmalade, and baked it in the oven until the marmalade was caramelised.
It wasn’t until I was on my own that I realised those canned hams were chopped and formed. Today I make actual bone-in hams (spiral cut), or a spiral-cut boneless ham section for smaller dinners.
Farther back then that, isn’t it? There is a reference in the Canterbury Tales to the “Dunmow Flitch,” where, in the village of Little Dunmow, they would give a flitch of bacon to any man on the day after his first wedding anniversary if he would swear that he and his wife had not argued with each other at all since their wedding; supposedly, it comes from the fact that such a claim was considered “all gammon.”
I like the little 1 pound chopped & formed cans for baking and pan frying when Spam is too salty. They’re usually $3-4 at Aldi or Walmart and have a really long shelf life. Best, you don’t have four pounds of problem after dinner.