1. (a.) Full of pain; causing uneasiness or distress, either physical or mental; afflictive; disquieting; distressing.

2. (a.) Requiring labor or toil; difficult; executed with laborious effort; as a painful service; a painful march.

3. (a.) Painstaking; careful; industrious.

Herculean aching achy acute affecting afflictive aggravating agonizing algetic annoying arduous assiduous atrocious backbreaking besetting biting bitter bleak bothersome burdensome burning careful cheerless comfortless conscientious cramping cruel crushing demanding deplorable depressing depressive detailed diligent discomforting dismal dismaying disquieting distasteful distressful distressing disturbing dolorific dolorogenic dolorous dreary earnest effortful exacting exasperating excruciating forced galling gnawing grave grievous griping grueling harassing hard hard-earned hard-fought harrowing harsh heavy hefty hurtful hurting irksome irritating joyless killing labored laborious lamentable meticulous mournful moving onerous operose oppressive painstaking paroxysmal pathetic piercing piteous pitiable plaguey poignant pungent punishing racking raw regrettable rigorous rueful sad saddening scrupulous sedulous sensitive severe sharp shooting smarting sore sorrowful spasmatic spasmic spasmodic stabbing stinging strained strenuous tender thorough thoroughgoing throbbing toilsome tormenting torturous touching tough troublesome troubling trying unappetizing uncomfortable unpalatable unpleasant unsavory uphill vexatious vexing wearisome woebegone woeful worrisome worrying wretched