noun
resin; tree sap
Refers to natural resin or sap from trees, often sticky.
松の木からヤニが出ている。
Resin is oozing from the pine tree.
noun
tobacco tar; nicotine buildup
Commonly refers to the sticky brown residue from tobacco smoke; often used when talking about cigarette filters or pipes.
タバコの吸い殻にヤニがたまっている。
Tar has built up on the cigarette butt.
noun
Used for the crusty discharge that forms in the corners of the eyes, especially after sleeping. Often appears in the compound 目やに.
See also: 目やに
朝起きたら目やにがついていた。
When I woke up in the morning, I had sleep in my eyes.
Rare kanji form; it is rarely used.
The origin is uncertain. It may be related to the verb やに (to be sticky) or an old mimetic root, but the exact derivation is unclear.