Biblical Hebrew

In the hiph'il binyan this verb means, "to save, deliver."
יָה is a m. sg. noun meaning, "Lord" and is commonly regarded as an abbreviated form of Yahweh. 
In combination the two parts would then mean, "Yahweh is salvation."
(Refer to Chapter 87.3 in Volume 5.) 


The Book of Isaiah is the first of the Latter Prophets in the Hebrew Bible and the first of the Major Prophets in the Christian Old Testament. 
It is identified by a superscription as the words of the 8th-century BCE prophet Isaiah ben Amoz, but there is extensive evidence that much of it was composed during the Babylonian captivity and later.

A consensus, held through most of the 20th century, is that the book comprises three separate collections of oracles: 
Proto-Isaiah (Chapters 1–39), 
containing the words of the 8th-century prophet Isaiah; 
Deutero-Isaiah (Chapters 40–55), 
the work of an anonymous 6th-century BCE author writing during the Exile; 
and Trito-Isaiah (Chapters 56–66), 
composed after the return from Exile.

Servant Songs
Also called the Servant Poems or the Songs of the Suffering Servant, 
are four songs in the Book of Isaiah in the Hebrew Bible, which include 

The songs are four poems written about a certain "servant of YHWH."
 God calls the servant to lead the nations, 
but the servant is horribly abused by them. 
In the end, he is rewarded.

The rest of this comprehensive Wikipedia article on the book can be read here.

Isaiah 9:5b
(An extract from the notes found in BHFA, Volume 5.)

 וַיִּקְרָא שְׁמוֹ   it will be called    his name

 פֶּלֶא יוֹעֵץ    marvel of    a counselor            Marvelous Counselor

 אֵל גִּבּוֹר     God     mighty                            Messiah

 אֲבִיעַד       father for ever                            Everlasting Father

 שַׂר־שָׁלוֹם   general of     peace                    Prince of Peace

Morphologically there should actually be a space between father and everlasting, but there is no footnote in BHS to indicate this, and lexicons list this as one word.

The construct masculine noun שַׂר is possibly a military term. We could think of 
God here as a captain or general in the present-day UN Peacekeeping Force.

The last six of the eight words in this verse obviously fall into three couplets, and some scholars are of the opinion the first two should probably also be taken together. These scholars then go on to point out that we then actually have four elements of one compound name.
divorcement - letter / deed / certificate of - it - where

Isaiah 50:1a
(An extract from the notes found in BHFA, Volume 5.)

              אֵי    זֶה              סֵפֶר                 כְּרִיתוּת
                 divorcement      letter / deed / certificate of    it     where

Noun, f. sg. meaning, "divorcement." 
This noun ocuurs only four times in the Hebrew Bible. 
Here, in Dt 24:1,3, and in Jer 3:8.

More on "divorce" here.