(a)significant, importantimportant in effect or meaning“a significant change in tax laws”, “a significant change in the Constitution”, “a significant contribution”, “significant details”, “statistically significant”
(a)crucial, importantof extreme importance; vital to the resolution of a crisis“a crucial moment in his career”, “a crucial election”, “a crucial issue for women”
(s)importanthaving or suggesting a consciousness of high position“recited the decree with an important air”, “took long important strides in the direction of his office”