laborious

adj.

[1]	arduous , arduous , backbreaking , burdensome , onerous , grueling , gruelling , strenuous , gruelling , hard , heavy , back-breaking , Herculean , operose , punishing , exhausting , taxing , toilsome , tiring , fatiguing , wearying , wearisome , toilsome , difficult , tough , hard , uphill , stiff
[2]	painstaking , detailed , careful , thorough , diligent , scrupulous , exhaustive , steady , steadfast , relentless , unrelenting , dogged , assiduous , sedulous , persevering , persistent , untiring , tireless , indefatigable , unremitting
[3]	industrious , hard-working , dogged , determined , unwavering , obstinate , stubborn , unflagging , obdurate
[4]	laboured , strained , forced , ponderous , overworked