nervous-Nellie adjective 1nervous Nellie noun 1forms 3 adjective1 •(informal) Characterized by worry or anxiety; having a weak, insecure personality.Woody Allen plays his most frazzled variation on the Woody we know best: a nervous-Nellie urban neurotic kvetching his way through life as a means of avoiding it. — 1993 nervous Nellie noun1 •(informal) A person whose personality and behavior are characterized by worry, insecurity, and timidity.Political opponents doubted his capacity, referred to him as "too nervous, too worried a little man," and remarked that his Senatorial colleagues used to refer to him humorously as "Nervous Nellie." — 1925 formsNervous Nellies · nervous Nellies · nervous nellies