This is the 11242nd most frequent Spanish word.
entenderlo
"To understand it."
The word 'entenderlo' is functioning as the object of understanding, referencing 'it', thus conveying the idea of comprehension towards something specific.
No puedo entenderlo sin más contexto.
I cannot understand it without more context.
Here, 'entenderlo' is utilized to indicate the act of comprehending the manual thoroughly; it's tied to deliberate effort to gain understanding.
Tuve que leer el manual para entenderlo bien.
I had to read the manual to understand it well.
In this case, 'entenderlo' specifies the understanding required before taking action, emphasizing prior comprehension.