Shibari
“tying” — the nominal form of shibaru, to tie or bind
A general Japanese word for tying, adopted in English as the umbrella name for Japanese-style rope bondage.
In Japanese, shibari is an ordinary word. It is the noun form of shibaru, to tie, and it applies to tying a parcel or lacing a shoe as readily as to tying a person. It carries no erotic sense on its own, which is why the word alone sounds oddly plain to Japanese speakers when English-speaking practitioners use it as the name of a whole discipline.
That adoption happened anyway, and it is now the most widely recognised English term for the practice. If you are looking for a class, this is the word most schools will use in their listings — which is a practical fact worth more than the etymological objection.
How the word is used in a class
In an English-language teaching context, shibari usually refers to the technical craft: the ties, the tension, the rope handling. An instructor saying “we will cover shibari fundamentals” is describing skills, not an intention for the room.