/ ˌʌnˌkærəktəˈrɪstɪk; NAmE / adjective
uncharacteristic (of sb) not typical of sb; not the way sb usually behaves :
The remark was quite uncharacteristic of her.
OPP characteristic
► un·char·ac·ter·is·tic·al·ly / -kli; NAmE / adverb :
The children had been uncharacteristically quiet.