Use 'intelligible' to describe speech that is clear and distinct enough to be heard properly. The teacher's instructions were perfectly intelligible even from the back of the classroom.
Pro Tip 2/3
Written Precision
Refers to writing that is clear and easy to read, with no ambiguity. Her essay was well-structured and intelligible, earning her top marks.
Pro Tip 3/3
General Understanding
Describes something that can be comprehended by anyone without specialist knowledge. The guidebook was written in an intelligible manner, suitable for tourists of all ages.