PAINFUL
irritating, painful
(adjective) causing physical discomfort; “bites of black flies are more than irritating; they can be very painful”
atrocious, abominable, awful, dreadful, painful, terrible, unspeakable
(adjective) exceptionally bad or displeasing; “atrocious taste”; “abominable workmanship”; “an awful voice”; “dreadful manners”; “a painful performance”; “terrible handwriting”; “an unspeakable odor came sweeping into the room”
painful
(adjective) causing physical or psychological pain; “worked with painful slowness”
afflictive, painful, sore
(adjective) causing misery or pain or distress; “it was a sore trial to him”; “the painful process of growing up”
Source: WordNet® 3.1
Etymology
Adjective
painful (comparative painfuller or more painful, superlative most painful)
Causing pain or distress, either physical or mental. [from 14th c.]
Afflicted or suffering with pain (of a body part or, formerly, of a person). [from 15th c.]
Requiring effort or labor; difficult, laborious. [from 15th c.]
(now rare) Painstaking; careful; industrious. [from 16th c.]
(informal) Very bad, poor.
Synonyms
• (full of pain): doleful, sorrowful, smartful, irksome, annoying
• (requiring labor or toil): laborious, exerting
Antonyms
• (causing pain): painless, painfree
Source: Wiktionary
Pain"ful, a.
1. Full of pain; causing uneasiness or distress, either physical or
mental; afflictive; disquieting; distressing Addison.
2. Requiring labor or toil; difficult; executed with laborious
effort; as a painful service; a painful march.
3. Painstaking; careful; industrious. [Obs.] Fuller.
A very painful person, and a great clerk. Jer. Taylor.
Nor must the painful husbandman be tired. Dryden.
Syn.
– Disquieting; troublesome; afflictive; distressing; grievous;
laborious; toilsome; difficult; arduous.
– Pain"ful*ly, adv.
– Pain"ful*ness, n.
Source: Webster’s Unabridged Dictionary 1913 Edition