"Sober" means being not drunk or under the influence of any drugs. It refers to a state of being clear-headed and in control of one's thoughts and actions. Full definition
He'll be happy to get you a burger with fries, and unless you like good old beer, you'll be staying sober for most of your time together. (freedatingservicesweb.com)
For entrepreneurs, it's yet another sign you may need to take a more sober view of things too. (inc.com)
Importantly is that the pant cut has to be in sober office style. (howomen.com)