Can you complete this grid of letters. Each line is a valid 5-letter word with its first and last letter missing.
The missing letters form a word when read downwards, and the same word appears both at the start and at the end.
What is the missing word?
| L | U | R | ||
| A | D | A | ||
| A | G | L | ||
| L | P | H | ||
| R | U | I |
Note: this puzzle is not interactive, and the squares cannot be clicked.