Intense mental effort

• The quality of being intent and concentrated
• The mental state of being preoccupied by something
• Complete attention

Wiktionary Word definitions in Wiktionary
n. 1 (context uncountable English) The state of being engrossed; concentration or preoccupation. 2 (context countable English) The fact or instance of writing in a legal document.

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Engrossment \En*gross"ment\, n. The act of engrossing; as, the engrossment of a deed. Engrossments of power and favor. --Swift. That which has been engrossed, as an instrument, legislative bill, goods, etc.

WordNet Word definitions in WordNet
n. complete attention; intense mental effort [syn: concentration , absorption , immersion ] the mental state of being preoccupied by something [syn: preoccupation , preoccupancy , absorption ] the quality of being intent and concentrated; "the intentness ...