1. Noun

   bar; bolt (e.g. on door); latch

   Usually written using kana alone

   ドアにかんぬきをし、錠をかけた。

2. double-arm lock

   SumoUsually written using kana alone

3. (rope) cinching

   Usually written using kana alone

Also written 貫木【かんぬき】kannuki