From Latin 'fortis' (strong) + 'facere' (to make) — literally 'to make strong,' kin to 'fort,' 'force,' and 'effort.'
Definition
To strengthen a place with defensive works so as to protect it against attack; to make stronger or more resilient.
The Full Story
Latin (via French)15th centurywell-attested
From Old French 'fortifier,' from Late Latin 'fortifīcāre' (to make strong, to strengthen, to furnish with walls and defences), a compound of Latin 'fortis' (strong, powerful, brave, sturdy) + '-fīcāre' (a combining form of 'facere,' to make — the same root that gives 'factory,' 'fact,' and 'fashion'). The PIE etymology of 'fortis' is debated but the dominant reconstruction connects it to *bʰerǵʰ- (high, elevated, towering), which names the strength of elevated fortified positions — the natural defensive advantage of height. This root produced Germanic words for mountain and fortified hill: German 'Berg' (mountain), Old English 'beorg' (hill, burial mound — surviving
Did you know?
TheGermanic cognate of 'fortify' is hiding in plain sight: 'borough' and '-burg' (as in Hamburg, Pittsburgh, Edinburgh) come from the same PIE root *bʰerǵʰ- (high place). A 'burg' was a fortified hilltop settlement — a placemade strong by elevation. Latin took the roottoward
in place-names like 'Lindisfarne' and in 'iceberg' from Dutch 'ijsberg'), and the pan-Germanic element '-burg / -burg / -borough' in place names worldwide — Salzburg, Pittsburgh, Edinburgh, Hamburg, Canterbury (Cantwarebyrig), Johannesburg — all originally
out) all derive from 'fortis.' To fortify something is literally to build it high and make it strong against assault — two meanings that were once physically identical. Key roots: *bʰerǵʰ- (Proto-Indo-European: "high, elevated"), facere (Latin: "to make, to do").