'Gladness' in the Bible

I said in my heart, 'Pray, come, I try thee with mirth, and look thou on gladness;' and lo, even it is vanity.

For he will not often consider the years of his life, because God keeps him occupied with the gladness of his heart.

Sorrow is better than laughter,For when a face is sad (deep in thought) the heart may be happy [because it is growing in wisdom].

In a day of prosperity be in gladness, And in a day of evil consider. Also this over-against that hath God made, To the intent that man doth not find anything after him.

Let your clothes always be white [with purity], and do not let the oil [of gladness] be lacking on your head.