attriter

noun2

1. •
   One who, or that which, attrites.
2. •
   One who has lost certain abilities in a language by learning and using a different language.

   • Attriters often experience lexical access problems, i.e. a discrepancy between what they would like to say, their communicative intention, and what they still know how to say in their L1. (Q52147493 (Q52147493) (2004), First Language Attrition: Interdisciplinary Perspectives on Methodological Issues, John Benjamins Publishing, →ISBN, page 196)