"knack" in the noun sense
1. bent, knack, hang
a special way of doing something
"he had a bent for it"
"he had a special knack for getting into trouble"
"he couldn't get the hang of it"
Source: WordNet® (An amazing lexical database of English)
Princeton University "About WordNet®."
WordNet®. Princeton University. 2010.
View WordNet® License