rugate

From Latin rugatus, past participle of rugare (“to wrinkle”), from ruga (“a wrinkle”).

• IPA^(key): /ˈɹuːɡeɪt/, /ˈɹuːɡət/

rugate (comparative more rugate, superlative most rugate)

1. Having alternate ridges and depressions; wrinkled.
   • c. 1848, James Dwight Dana, Zoophytes:

     Unifacial, superior surface transversely rugate, with minute oririmes at the bottom of the furrows

2. Having a varying refractive index.
   • 2002, Bruce E. Perilloux, Thin-film Design, page 7:

     Rugate coatings typically consist of a single layer deposited onto a substrate where the refractive index of the layer continuously changes as a function of depth.

   • 2013, John Polo, Tom Mackay, Akhlesh Lakhtakia, Electromagnetic Surface Waves: A Modern Perspective, page 193:

     Researchers have focused on various manufactured periodically nonhomogeneous dielectric materials, including rugate filters and periodically multilayered materials.

• bewrinkled, rugose, wrinkly; see also Thesaurus:wrinkled

• Tuareg, Tauger, truage, argute, Ugarte

rugate

1. second-person singular voseo imperative of rugar combined with te