causing misery or pain or distress
"it was a sore trial to him"
"the painful process of growing up"
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"
causing physical discomfort
"bites of black flies are more than irritating; they can be very painful"
Causing pain or distress, either physical or mental.
"The reminder of his lost childhood was painful to hear again."
In plain English: Painful means causing physical hurt or emotional distress that makes you want to stop what you are doing immediately.
"The pinprick from the needle was surprisingly painful, but he pushed through quickly to get his shot done."
Usage: Use painful to describe anything that causes immediate physical hurt or significant emotional suffering. It is often confused with the noun form of pain itself, but remember it functions strictly as an adjective modifying a subject like "experience" or "memory."
The word painful comes from Middle English and is formed by combining the noun "pain" with the suffix "-ful." It entered modern usage as a direct description of something causing physical or emotional suffering.