Adobe Reader is not present in repositories for Ubuntu 14.04. On the other hand installing the software from package (.deb) downloaded directly from Adobe’s website is somehow problematic. Ubuntu’s package manager informs that the Adobe Reader 9 installer package is incorrect and risky.
The best approach is to make use of a repository from an older Ubuntu version. Just open a terminal and type following commands:
sudo bash echo -e '# for acroread\ndeb http://archive.canonical.com/ubuntu/ raring partner' > /etc/apt/sources.list.d/raring-partner.list apt-get update apt-get install acroread exit