The compound "truth-telling" is a transparent modern English formation. Its first element, "truth," originates from the Old English abstract noun 'trēowth,' which itself is built on the adjective 'trēowe' (faithful, true), a concept rooted in Germanic notions of fidelity and constancy. The second element, "tell," descends from the Old English verb 'tellan,' which originally meant "to count" before evolving to mean "to recount a narrative." The suffix "-ing" is a productive Germanic agentive and participial suffix. Therefore, the word's literal construction—"the act of narrating truth"—perfectly captures its modern meaning of honest disclosure or the habitual quality of being honest.

Structure: truth (true) + tell (to narrate) + ing (noun/adjective suffix) truth: From Old English 'trēowth' (faith, fidelity, truth), of Germanic origin. Functions as a noun, representing the concept of fact or reality. tell: From Old English 'tellan' (to count, relate, recount), of Germanic origin. Functions as a verb root meaning to narrate or inform. ing: A suffix of Germanic origin forming verbal nouns (gerunds) and participial adjectives.