«وفصاحة الكلام: سلامته من تنافر الكلمات مجتمعة، ومن ضعف التأليف، ومن التعقيد مع فصاحة كلماته»
An utterance is eloquent when its words together are free from discord, its syntax is not defective, its meaning is not entangled, and each individual word is eloquent.
The definition imposes four requirements: absence of word-sequence discord, absence of defective construction, absence of complexity that conceals the meaning, and eloquence of the component words.
The final condition matters. A sentence with one individually defective word cannot be declared eloquent merely because the rest sounds smooth.