Adjective

(-)

Not able; lacking a certain ability.

*{{quote-news, year=2011, date=December 21, author=Tom Rostance, work=BBC Sport

, title= Fulham 0-5 Man Utd , passage=Fulham switched off as Giggs took a quick corner to Valencia. He played it back to Giggs, whose cross was headed in by Nani with the lurking Rooney unable to add a touch. }}

*{{quote-magazine, date=2013-06-28, author=(Joris Luyendijk)

, volume=189, issue=3, page=21, magazine=(The Guardian Weekly) , title= Our banks are out of control , passage=Seeing the British establishment struggle with the financial sector is like watching an alcoholic […].  Until 2008 there was denial over what finance had become. […]  But the scandals kept coming, […]. A broad section of the political class now recognises the need for change but remains unable to see the necessity of a fundamental overhaul.}}

Are you unable to mind your own business or something?

Adjective

(wikipedia undefined) (-)

Lacking a definition or value.

(mathematics, computing) That does not have a meaning and is thus not assigned an interpretation.

The result of division by zero is undefined .