What family word do the letters in the grey boxes in Exercise 1 spell?

Step-by-step Solution:

1. Identify the grey boxes in the crossword. These are at positions 1a, 2a, 3a, 9a, and 10a.
2. The letters in these grey boxes are: G (from GRANDSON), A (from AUNT), D (from GRANDDAUGHTER), U (from UNCLE), and N (from UNCLE).
3. Arranging these letters in order: G, A, D, U, N.
4. The word formed by these letters is GADUN. However, looking at the provided image, the grey boxes are part of the answers to the clues. Let's re-examine the filled crossword. The grey boxes indicated by 'a' and 'n' seem to correspond to specific letter positions within the solved words, not necessarily a separate set of clues. It is more likely that the question refers to the letters that are boxed in the grid itself, which are part of the answers. Upon closer inspection, the grey boxes are typically where the answers to the clues are written. The question asks for the letters in the *grey boxes*. In the provided image, the cells for clue 10 Across (UNCLE) are shaded grey.
5. The word for clue 10 Across is UNCLE.
6. The letters in the grey boxes (for clue 10 Across) are U, N, C, L, E.
7. These letters spell the word UNCLE.

Answer: UNCLE