a meal is whatever you happen to be eating -i t should be a combination of carbs/protein/fats and within your daily calorie range for the day.
I'm not a fan of the five "meal" a day approach, my schedule just doesnt allow for it... I have 3 normal meals a day, breakfast, lunch and dinner, then add in a morning snack, afternoon snack and dinner snack and wth some pre planning can keep it at about 2200 calories for the day
Snacks for me might be fruit, or goat cheese and whole grain crackers, a high fiber tortilla w/ hummus and vegetables, a yogurt - it depends on my mood but it's generally in the 150 calorie range.