tenet

noun

1. any opinion, principle, doctrine, dogma, etc., especially one held as true by members of a profession, group, or movement.

noun

1. a belief, opinion, or dogma

n.“principle,” properly “a thing held (to be true),” early 15c., from Latin tenet “he holds,” third person singular present indicative of tenere “to hold, to keep, to maintain” from PIE root *ten- “to stretch” (cf. Sanskrit tantram “loom,” tanoti “stretches, lasts;” Persian tar “string;” Lithuanian tankus “compact,” i.e. “tightened;” Greek teinein “to stretch,” tasis “a stretching, tension,” tenos “sinew,” tetanos “stiff, rigid,” tonos “string,” hence “sound, pitch;” Latin tendere “to stretch,” tenuis “thin, rare, fine;” Old Church Slavonic tento “cord;” Old English thynne “thin”). Connection notion between “stretch” and “hold” is “to cause to maintain.” The modern sense is probably because tenet was used in Medieval Latin to introduce a statement of doctrine.