c. 1600, "separate, separated from others that are similar or contiguous" (a sense now obsolete), past-participle adjective from distinguish. Sense of "better known than others in the same class, separated from the generality by superior abilities, character or achievement," hence "famous, celebrated," is by 1714; meaning "having an air of distinction" is from 1748.
our distinguished professor
his distinguished bearing
distinctive
distinctly
distingue
distinguish
distinguishable
distinguished
distort
distortion
distract
distracted
distraction