Definitions for yearlongˈyɪərˈlɔŋ, -ˈlɒŋ
Random House Webster's College Dictionary
lasting for a year.
Origin of yearlong:
lasting through a year
"attending yearlong courses"
Per year (mostly used to discuss animal farming)
Throughout every year; not seasonally
Lasting one year, or approximately so; of or relating to a timespan of one year.
Which lasts throughout every year; which is not seasonal