CaseIssue to investigate
Known meaning; difficult articulationTanafur
Smooth pronunciation; obscure intended senseGharaba
Both sound and sense are difficultCheck both separately
A learner might pronounce a word correctly while failing to grasp its intended meaning without lexical help. That prompts an inquiry into gharaba, but the learner's ignorance is not conclusive proof of technical obscurity.
Conversely, clarifying a word's meaning does not automatically eliminate a distinct phonetic problem.