🔼The name Bul in the Bible
The name Bul occurs only once in the Bible. It's the Canaanite name for the eighth month, which was the month of harvest, corresponding to our months October-November.
It's mentioned only in relation to the building of Solomon's temple which commenced in the month Ziv (the month of the blossoms) and was completed seven years later, in the month Bul (1 Kings 6:38). This obviously reflected both the Sabbatical cycle and the agricultural year.
Note that the names Ziv and Bul are Canaanite names. In Hebrew these names would be called Iyyar (איר) and Marcheshvan (מרחשון) or Cheshvan (חשון), but these Hebrew names don't occur in the Bible.
🔼Etymology of the name Bul
Some scholars have proposed that the name Bul (בול) may have something to do with the name Baal (בעל) and although Baal was a fertility and agricultural deity, it's more plausible that the name of the month of the harvest derives from the verb יבל (yabal), meaning to produce, and particularly the identical noun בול (bul), meaning produce or outgrowth:
The name Bul as name for the month of the harvest means Produce or Outgrowth.