\Is-\
See {Iso-}.

\Is\, v. i. [AS. is; akin to G. & Goth. ist, L. est, Gr. ?,
Skr. asti. [root]9. Cf. {Am}, {Entity}, {Essence}, {Absent}.]
The third person singular of the substantive verb be, in the
indicative mood, present tense; as, he is; he is a man. See
{Be}.
Note: In some varieties of the Northern dialect of Old
      English, is was used for all persons of the singular.
            For thy is I come, and eke Alain.  --Chaucer.
            Aye is thou merry.                 --Chaucer.
Note: The idiom of using the present for future events sure
      to happen is a relic of Old English in which the
      present and future had the same form; as, this year
      Christmas is on Friday.
            To-morrow is the new moon.         --1 Sam. xx.
                                               5.