adverb
Describes something that is full of wrinkles or creases, often with a soft or shriveled appearance. Used for fabric, skin, paper, etc.
See also: 皺くちゃ
このシャツ、洗ったらシワシワになっちゃった。
This shirt got all wrinkled after washing.
おばあちゃんの手はシワシワだけど、温かい。
Grandma's hands are wrinkled, but warm.
Kanji spelling; rarely used.
皺くちゃ is a more emphatic, often negative term for something extremely crumpled or wrinkled, while シワシワ is a softer, more neutral description.
Reduplication of しわ (wrinkle), forming a mimetic adverb describing a wrinkled state.