Hebrew, “Understanding.” Resting between but below Da’at and Chokhma, and between but above Chesed and Gevurah, Binah is the understanding that comes from Da’at (knowledge) and Chokhma (wisdom). It can only be reached after one is cleansed by Chesed (God’s mercy) and Gevurah (God’s Holy Fire/Judgement). Binah is the Holy Spirit giving us intuitive understanding, contemplation by Christ’s Grace. It is the womb, a temple inside us housing the Spirit of God. It is the birth of the soul.
In a mundane way, Binah may also be seen as deductive reasoning. It is God helping us understanding one idea pondering or gazing at another one. Binah can be a rational process that within a person which guides us to develop an idea to its fruition. Thus scientific breakthroughs and revelation giving us guidance can both be Binah; understanding from divine knowledge and wisdom given us by God.
See Book of Remembrance 1:21, 33:35-37.