Letter Quest: Grimm's Journey Remastered

Each row consists of 5 letters, so you'll naturally need to make words 5 or more letters long to get this achievement. If you're using a word solver, this will almost assuredly come naturally. If not, you can purposely manipulate the board to get tiles where you need them for this achievement. For example if you have a row with PPADE you can use the 'D' in a word with lower row letters to try to get an 'R' in its place (to spell PAPER), or use a 'P' to try to get an 'R' (to spell PARED).

In general, though, I wouldn't focus on this achievement as it will likely unlock naturally while going for the other achievements.