Individual with dagger, oddly nervous (2,4)
I believe the answer is:
on edge
'nervous' is the definition.
(thesaurus)
'individual with dagger oddly' is the wordplay.
'individual' becomes 'one'.
'with' says to put letters next to each other.
'oddly' indicates alternate letters.
The alternating letters of 'dagger' are 'dge'.
'one'+'dge'='ON EDGE'
(Other definitions for on edge that I've seen before include "stressed" , "Nervy, tense and irritable" , "Twitchy" , "'Tense, nervous (2,4)'" , "Anxious, nervy" .)