In grammar, a supine is a form of verbal noun used in some languages. The term is most often used for Latin. It is one of the four principal parts.
There are two supines, I (first) and II (second). They are originally the accusative and ablative forms of a verbal noun in the fourth declension, respectively. The first supine ends in -um. It has two uses. The first is with verbs of motion and indicates purpose. For example, "Gladiatores adierunt pugnatum" is Latin for "The gladiators have come to fight", and "Nuntii gratulatum et cubitum venerunt" is Latin for "The messengers came to congratulate and to sleep". The second usage is in the future passive infinitive, for example "amatum iri" means "to be about to be loved". It mostly appears in indirect statements, for example "credidit se necatum iri", meaning "he believed that he was going to be killed".
The second supine can be used with adjectives but it is rarely used, and only a few verbs traditionally take it. It is derived from the dativus finalis, which expresses purpose, or the ablativus respectivus, which indicates in what respect. It is the same as the first supine without the final -m and with lengthened "u". "Mirabile dictū", for example, means "amazing to say", where dictū is a supine form.
In English grammar, the term "supine" is sometimes used to refer to the to-infinitive, in sentences like "To err is human; to forgive divine."
In Swedish, the supine is used with an auxiliary verb to produce some compound verb forms (perfect forms). See Swedish grammar.
In Estonian, the supine is called "ma-tegevusnimi" (lit. "ma-action name") because all the words in supine have "ma" in the end (as in "tegema", "jooksma", "kõndima"), and they act similarly to the Latin example. The supine is also the common dictionary form for verbs.