What is tending to improve, beneficial; growing better. -- Im*prov"ing*ly, adv. Improving lease (Scots Law), an extend lease to induce the tenant to make improvements on the premises called?

improving — Tending to improve, beneficial; growing better. -- Im*prov"ing*ly, adv. Improving lease (Scots Law), an extend lease to induce the tenant to make improvements on the premises. (Webster's 1913.)

Sources