If the responses on the previous thread where this exact “learner/earner” discussion took place over five years ago is any indication, most responses there define learner/earner as simply spending less years in kollel:
In fact, I didn’t see anyone there define it as being a boy who will both work and learn full-time simultaneously. While that might not prove that definition wrong, it appears in the popular lexicon it simply means less years in kollel coupled with kovea itim.