fidibus
fidibus is a Latin form of fides, meaning “faith, trust; loyalty; promise”. It is the ablative plural feminine noun.
Found 55 times in the Latin texts on Socratos.
Where it is used
Cicero, De Republica 2.69: … mitationem sui vocet alios, ut sese splendore animi et vitae suae sicut speculum praebeat civibus. Ut enim in fidibus aut tibiis atque ut in cantu ipso ac vocibus concentus est quidam tenendus ex distinctis sonis, quem inmutatu …
Boethius, De consolatione philosophiae 3.M2.6: Fidibus lentis promere cantu.
All forms of fides (declension table)
Source: Socratos (socratos.org), a free reader for Ancient Greek and Latin. Grammar from the Perseus Treebank and Morpheus; dictionary entries from Lewis & Short, A Latin Dictionary (Perseus Digital Library, CC BY-SA). Counts are from the texts on Socratos.