[Yusf]

In my book, the reaction between halohenoalkane and alcoholic alkali is described as Nucleophilic elimination. But can I call it condensation, as a small molecule is lost?

[Fr_Chuck]

No because it is more than a loss of a molecule.
Net effect is that you replace the -Cl by -Nu, and hydrogen chloride is formed as well.
Since the initial attack is by a nucleophile, and the overall result is substitution, it would seem reasonable to describe the reaction as nucleophilic substitution. However, the reaction happens in two distinct stages. The first involves an addition reaction, which is followed by an elimination reaction where HCl is produced. So the mechanism is also known as nucleophilic addition / elimination

Even substitution is incorrect but a closer term.