Articulation disorder means the absence of or incorrect production of speech sounds or phonological processes that are developmentally appropriate (e.g. lisp, difficulty articulating certain sounds, such as l or r).
When an articulation issue occurs in the first language, it is often heard in the second language as well. I have a student who “fronts” (or velar fronting, meaning sounds that should be produced in the back of the mouth are produced in the front), so /k/ becomes /t/, and /g/ becomes /d/. In English he says “bicytle” for bicycle, and in Somali, his first language says “baastiil” instead of “baaskiil”.