to have no significance, be unimportant
X ничего не значит - thing X doesn't mean anything (a thing)
thing X doesn't matter
thing X is inconsequential
person X doesn't have any clout (say (in anything), pull etc)
person X is a nonentity (in his family (at work etc)).
(Кабанова:) Ведь ты... с ней (с женой) в законе живешь. Али ( substand = или), по-вашему, закон ничего не значит? (Островский 6). (К..) After all.. .you're living with her (your wife) in lawful marriage. Or, to your way of thinking, doesn't lawful marriage mean anything? (6a).
(Хороших:) Думаешь, заступился он за тебя, значит, что ж?.. Да ничего не значит!.. Не замечал он тебя и не замечает (Вампилов 2). (Kh :) You think because he defended you it means something, is that it?. .But it doesn't mean a thing!...He never noticed you before and he doesn't now (2b).
Большой русско-английский фразеологический словарь. — М.: ACT-ПРЕСС КНИГА. С.И. Лубенская. 2004.