Dead On
Okay. Fine. No problem. The standard Belfast and Ulster phrase for casual agreement or confirmation. Also (of a person) sound, decent, reliable: 'he's dead on' = he's a decent fellow.
Etymology
Built from standard English 'dead' (= completely, exactly, used as an intensifier) plus 'on' (= correct, target-hit). The construction 'dead on the mark' (= exactly right) is older English; the Belfast usage abbreviated it to a stand-alone 'dead on' meaning right, correct, fine. The shift from the literal sense (= exactly correct) to the social sense (= a decent person) is a small Hiberno-English semantic broadening.
In a sentence
"Could you mind the wains for an hour?" "Dead on - send them down."
Historical notes
Dead on operates as both an answer and a character description in Ulster speech. As a response - 'will you give me a lift?' 'dead on' - it does the work that 'no bother' or 'sure thing' does elsewhere. As a description - 'your man's dead on' - it bestows social approval: he's reliable, trustworthy, the kind of person you'd lend a tenner to. The shift between the two uses is contextual and rarely confusing.
Sources
- Macafee, Caroline. A Concise Ulster Dictionary. Oxford University Press, 1996. · dictionary