bastille.

From Middle French bastille, from Old French baastel, basstel (“fortification; fortified tower; temporary fortification constructed for attack or defence; (small) castle or fortress”) (compare Medieval Latin bastīle), from bastide (“fortification; fortress”) with the ending modified after nouns ending in -ille (from Latin -īle (suffix forming place names)). Bastide is derived from Old Occitan bastida (“fortification; (Provence) country mansion”), from bastir (“to build, construct”) + -ida (suffix forming nouns); while bastir is from Medieval Latin bastīre, the present active infinitive of *bastīre, from Frankish *bastijan (“to sew; to weave”), from Proto-West Germanic *bast (“fibre; rope”); further etymology uncertain, perhaps from Proto-Indo-European *bʰask- ~ *bʰasḱ- (“bundle, heap, load”) but this is disputed. Compare typologically Russian опло́т (oplót), плете́нь (pleténʹ) (akin to плести́ (plestí)).