changing names of 'classifieds' & 'listings'

I am running DIRECTORY and CLASSIFIEDS with MEMBERSHIP.

Where listed on site, directory is known as Listings and classifieds is known as classifieds.

This is causing confusion with my members who forget which is which. So I would like to change the names.

I have attached a screen grab of the profile page which highlights the user's problem.

I would like both the names 'classifieds' and 'listings' renamed to something else (enterprise zone and business opportunities respectively). Is anyone able to point me in the direction of achieving this?

Many thanks.