Each pair of definitions is for two words, where the second word is the first word with a letter deleted (example: brand & band). The length of the first word in each pair is provided, along with the position of the deleted letter to obtain the second word.
1) any of the display rooms of a museum (7 letters) & (delete 6th letter) a ship's kitchen
2) a small rodent (5 letters) & (delete 2nd letter) to meditate
3) powdery (5 letters) & (delete 3rd letter) an action related to one's occupation
4) to clear someone of blame (9 letters) & (delete 1st letter) to direct attention toward something