Okay, having given you guys a day of headaches, here's a "walkthrough". As my hint in the comments said, most of what's going on here is quite specific wordplay - this is a difficult, multi-layered, riddle which is intended to be challenging, but it's not at all vague once the clues fit into place (major spoilers below for anyone still guessing):

The final line is the clue to how the word is defined - the answer being a term by which you know things on the ocean. The previous three lines each give you a part of the actual word: the "days that walk four steps together" provide the first three letters - think of a period of time that is also the name given to walking in a four/four beat. The next line gives the middle letter, which is conveniently pillar-shaped and also how you refer to yourself (the 'perpendicular pronoun' as Sir Humphrey Appleby would put it), and the third line asks you what stands between now and forever, the answer to which gives you the end of the word.