intelligible
Concise Oxford English Dictionary © 2008 Oxford University Press:
intelligible /ɪnˈtɛlɪdʒɪb(ə)l/
▶adjective able to be understood.
■ Philosophy able to be understood only by the intellect.
– derivatives
intelligibility noun,
intelligibly adverb.
intelligibility noun,
intelligibly adverb.
'intelligible' also found in these Oxford entries:

