Supine

In Latin linguistics, the term supine refers to a non-finite form of the verb that expresses purpose and other adverbial notions.

Examples
Latin

Pater venit amicum gratula-tum.

father came friend.ACC congratulate-SUP

'Father came to congratulate his friend.'

Polysemy
The term supine is also used in Swedish linguistics, for something rather different.

Origin
The Latin adjective supinus means 'facing upwards, lying on one's back, indifferent'. According to Benveniste (1948), the metaphor is the following: "Le supin verbal est indifférent à la voix, au temps et au mode, par comparaison à l'attitude d'un homme nonchalamment couché." [The verbal supine is indifferent to voice, tense and mood, comparing with the attitude of a person lying nonchalantly.]

See Richter 1856-1860 for an early detailed study of the Latin supines.