mid-15c., "fortified place, stronghold," from Middle French fort, from noun use in Old French of fort (adj.) "strong, fortified" (10c.), from Latin fortis "strong, mighty, firm, steadfast," from Old Latin forctus, possibly from PIE root *bheregh- "high, elevated," with derivatives referring to hills and hill-forts (cf. Sanskrit brmhati "strengthens, elevates," Old High German berg "hill;" see barrow (n.2)).
Assume responsibility, especially in another's absence; also, maintain a secure position. For example, Harry did a good job of holding the fort until his boss recovered, or Can you hold the fort in the kitchen? This expression has been traced to an order given by General William Tecumseh Sherman in 1864, which was repeated as “Hold the fort [against the enemy at Allatoona] at all costs, for I am coming.”
