It is the possessive form of "alb" (لب), which means "heart". The prefix "al-" signifies possession, similar to the English "my" or "your".
Here are some examples of how "albi" can be used in a sentence:
* "Albi maktoub bihi asmak": "My heart is inscribed with your name."
* "Albi ya'rif al-haqiqa": "My heart knows the truth."
* "Albi moshtaq lak": "My heart yearns for you."
It's a very common and heartfelt word in Arabic, often used in poetry and love songs.