from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Extremely clear and plain to see.
Sorry, no etymologies found.
For it was plain as a pikestaff whither he was bound, and if he thought he could come round me with his blood-brotherhood fustian, he was well out of court.
Of course she did know why: she was as plain as a pikestaff despite the weight she was so delighted at gaining, fancying that her breasts were now quite as nice as most, her waist as small, her hips as properly hippy.
And it was plain as a pikestaff that they hadn't any.