VALEDICTORIAN
valedictorian, valedictory speaker
(noun) the student with the best grades who usually delivers the valedictory address at commencement
Source: WordNet® 3.1
Etymology
Noun
valedictorian (plural valedictorians)
(US, Canada, properly) The individual in a graduating class who delivers the farewell or valedictory address, often the person who graduates with the highest grades.
(US, Canada, colloquial) The individual in a graduating class who graduates with the highest grades.
Synonyms
• dux
Source: Wiktionary
Val`e*dic*to"ri*an, n.
Definition: One who pronounces a valedictory address; especially, in
American colleges, the student who pronounces the valedictory of the
graduating class at the annual commencement, usually the student who
ranks first in scholarship.
Source: Webster’s Unabridged Dictionary 1913 Edition