Archaic form meaning heavy, burdensome, or oppressive; causing difficulty or hardship.
From burthen (archaic 'burden') + '-some' suffix meaning 'full of' or 'characterized by.' This reflects older English adjective formation patterns.
Older writers used 'burthensome' for things that weighed heavily on the soul or body—a 'burthensome task' sounded more poetic and dramatic than simply saying it was hard!
Complete word intelligence in one call. Free tier — 50 lookups/day.