society > armed hostility > defence > defensive work(s) > fort or fortified town > [noun] > small fort (6)
A little fort or fortress.
Fortification A small fort or earthwork; esp. one built to defend a ford, pass, castle-gate, etc., or erected as a counter-fort.
In early use = fortress, n.; by modern writers chiefly used for: ‘A small outwork of a fortification’ (W.); a small fort.
A small fort; a field-fort.