Describes sexually improper or indecent behavior, speech, or content. Can be used for both people and things.
He was arrested for committing an indecent act in public.
He always tells lewd jokes.
That movie has too many obscene scenes.
He got drunk and started spouting obscene remarks.
She felt uncomfortable being looked at with lewd eyes.
いやらしい describes a person's creepy or distasteful lewdness, while 淫ら more directly labels an act or content as sexually indecent.
下品 means vulgar or crude in a general sense, while 淫ら specifically points to sexual impropriety.
Standard kanji spelling.
Kana spelling is common in everyday writing, especially when the kanji is considered difficult or overly formal.
Rarely used kanji form.
The historical derivation is uncertain. The kanji 淫 and 猥 both carry meanings related to indecency or excess, and are conventionally associated with this word.