Entry 1 sense Webster, 1913

Is

/ĭz/ · IPA /ɪz/

01 v. i. The third person singular of the substantive verb be, in the indicative mood, present tense; as, he is; he is a man. See Be.

1.
The third person singular of the substantive verb be, in the indicative mood, present tense; as, he is; he is a man. See Be. See: Be
“For thy is I come, and eke Alain.” — Chaucer.

“Aye is thou merry.” — Chaucer.

“To-morrow is the new moon.” — 1 Sam. xx. 5.