עזר

Abarim Publications' online Biblical Hebrew Dictionary

Scholars have identified two separate roots עזר ('zr), probably because the meaning of one specific word — namely עזרה ('azara) — doesn't fit the others:

עזר I

The verb עזר ('azar I), means to help, support. This verb is used in the Bible in all the expected ways, but, as HAW Theological Wordbook of the Old Testament notes, most often in military situations. During battle, human party's rush to each other's aid (Ezekiel 30:8), but most often God is doing the helping (1 Chronicles 12:18).

That this verb shows up mostly in combat scenes has probably more to do with the Bible's going themes than with the nature of this verb. When God sees Adam all by himself, he concludes that Adam needs a helper, and creates Eve (Genesis 2:8). It does, however, show that Eve was not Adam's secretary or maid, but rather an indispensable pillar. In any situation described in the Bible by this verb, without the helper, the person who needed the help would either die or fade away. So God "helps" the fatherless (Psalm 10:14), the ill (Psalm 28:7), those who suffer great spiritual discomfort (Psalm 54:4), and the poor (Psalm 72:12).

This verb yields:

The identical masculine noun עזר ('azar), meaning help (Isaiah 30:5).
The feminine noun עזרה ('ezra), also meaning help (Jeremiah 37:7).

עזר II

The identical root עזר ('zr II) isn't used in the Bible but its sole derivative is: the feminine noun עזרה ('azara) meaning enclosure (Ezekiel 43:14, 2 Chronicles 4:9).