Brunch is a late morning meal that serves a mix of breakfast and lunch dishes. The word brunch is a combination of the words breakfast and lunch.
A crunch is a crackling noise that some things make as you break it. If you step on loose snow it will crunch under your feet. Many breakfast cereals make a crunch noise as you eat them.
Lunch is a meal you eat in the middle of the day. Most people have sandwiches for lunch, but you can have almost anything. Some people have salad for lunch, other people will have a steak.
Punch is a name given to any mixed drink, alcoholic or not, that has fruit juice in it. Punch is usually served in a large bowl, with a ladle for people to help themselves to the drink.