Fortlet

A small fort for a moderately sized garrison - but not so large as to hold a full unit of soldiers, such as a cohort or legion. Usually spaced about a day's march from another military base they may be outposts or with a specific function, such as guarding a bridge or road. Examples of fortlets guarding roads are at Chew Green (phases II and IV), ...
Found on http://www.encyclo.co.uk/local/20766

Fortlet

Fort'let noun A little fort. [ R.] Bailey.
Found on http://www.encyclo.co.uk/webster/F/66

Fortlet

• (n.) A little fort.
Found on http://thinkexist.com/dictionary/meaning/fortlet/
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