telling

nouns

an act of narration
"he was the hero according to his own relation"; "his endless recounting of the incident eventually became unbearable"
is derived from
informing by words
is derived from
disclosing information or giving evidence about another
is derived from

adjectives

disclosing unintentionally
"a telling smile"; "a telltale panel of lights"; "a telltale patch of oil on the water marked where the boat went down"
powerfully persuasive
"a cogent argument"; "a telling presentation"; "a weighty argument"
producing a strong effect
"gave an impressive performance as Othello"; "a telling gesture"