"Buck Sergeant" is used in reference to a Sergeant (E5) - the lowest grade of Sergeant - as opposed to Staff Sergeant, Sergeant First Class, Master Sergeant, First Sergeant, etc.
It typicly means a Trainne who has passed Special forces Assessment and selection and is in the Special forces Qualification course
Sergent first class
Antoine Louis François Sergent dit Sergent-Marceau died in 1847.
Antoine Louis François Sergent dit Sergent-Marceau was born in 1751.
Brian Sergent's birth name is Brian Clifford Sergent-Shadbolt.
Michel Sergent was born in 1943.
René Sergent was born in 1865.
René Sergent died in 1927.
Bernard Sergent was born in 1946.
Brian Sergent is 173 cm.
Jesse Sergent was born on July 8, 1988.
Jesse Sergent was born on July 8, 1988.
Lucien-Pierre Sergent died in 1904.