What is Psalm 555?

Answer 1

In the King James version, and in (most/all)? versions of the Bible

there are 150 Psalms - so there isn't a Psalm 555

Biblical books, chapters and verses are generally referenced

Book chapter:verse so that the fourth verse in the second chapter of the Book of Exodus would be given as Exodus 2:4

Under that referencing system, your question could mean "Psalms 5:55" or "Psalms 55:5"

As there are not 55 verses in Psalm 5, this could only mean Psalm 55:5 (providing there are no typographical errors in the question)....

Psalms 55:5 Fearfulness and trembling are come upon me, and Horror hath overwhelmed me.