optative mood
A grammatical mood expressing a wish or desire. Used in linguistic descriptions of Japanese and other languages.
日本語の「～たい」は祈願法の一種と見なされることがある。
The Japanese '~tai' is sometimes regarded as a kind of optative mood.
Compound of 祈願 (kigan, 'prayer' or 'wish') and 法 (hō, 'mood' in grammatical context). A calque from Western linguistic terminology.