Greatest or son of Henry
A modern American invention, Mckendra likely combines the popular 'Mc' prefix with the name Kendra. Kendra itself has roots meaning 'greatest champion' or 'high hill', while the 'Mc' prefix traditionally denotes 'son of' in Gaelic patronymics.
Less common today
Mckendra isn't in the latest US Top 1000. It last peaked at #8,695 in 1999.
US births per 5-year period, 1990βpresent (SSA data).