This is a list of surnames in which the usage is Belgian; and the number of syllables is 3.
Beethoven Dutch (Archaic)From a place name derived from Dutch
beet "beet, beetroot" and
hoven "farms". This name was borne by the German composer Ludwig van Beethoven (1770-1827), whose family was of Flemish origin. The surname is now mostly extinct.
Charbonneau FrenchDerived from a diminutive form of French
charbon "charcoal", a nickname for a person with black hair or a dark complexion.
Chevalier FrenchFrom a nickname derived from French
chevalier meaning
"knight", from Late Latin
caballarius "horseman", Latin
caballus "horse".
Delacroix FrenchMeans
"of the cross" in French. It denoted one who lived near a cross symbol or near a crossroads. A notable bearer was the French painter Eugène Delacroix (1798-1863).
Van den Berg DutchMeans
"from the mountain", derived from Dutch
berg meaning "mountain".