(of a person) able to put thoughts and feelings into clear speech

clearly, coherently spoken

(of arguments) strong and convincing

effective

showing feelings, personality etc

telling, revealing

something that (often by mistake) causes something secret to be known

revealing

serious; very sad and disappointing; (a place with) a hole dug in the ground for a dead body

serious; gloomy

of great influence or value

valuable, substantial

having power to affect people or situations

effective, powerful

full of facts, interest

significant

deserving to be remembered because special

noteworthy, significant

extremely important or serious

important; serious

causing an effect on a person's feelings or emotions

affecting, exciting

deserving to be noted; remarkable

important

solidly or strongly built or made

important, ample

that cannot be forgotten

memorable

of, connected, with, necessary for, living; greatest; indispensable

essential

(of colours etc) strong and bright; lively, active; clear and distinct

intense, powerful

speaking well, politely

clearly, coherently spoken