arduous (
http://definr.com/arduous)
adj 1: characterized by toilsome effort to the point of exhaustion;
especially physical effort; "worked their arduous way
up the mining valley"; "a grueling campaign"; "hard
labor"; "heavy work"; "heavy going"; "spent many
laborious hours on the project"; "set a punishing
pace" [syn:
backbreaking,
grueling,
gruelling,
hard,
heavy,
laborious,
labourious,
punishing,
toilsome]
2: taxing to the utmost; testing powers of endurance; "his
final, straining burst of speed"; "a strenuous task";
"your willingness after these six arduous days to remain
here"- F.D.Roosevelt [syn:
straining,
strenuous]
3: difficult to accomplish; demanding considerable mental
effort and skill; "the arduous work of preparing a
dictionary"