I looked at the definition for "learner":
a person who is still learning something(Cambridge)
a person who is learning; student; pupil; apprentice; trainee.(Dictionary.com)
1.someone (especially a child) who learns (as from a teacher) or takes up knowledge or beliefs
2.works for an expert to learn a trade(TFD-Thesaurus)
someone who is learning something; beginner(Collins, En-Fr)
A learner is someone who is learning about a particular subject or how to do something.(Collins Learner's)
1 : a person who learns
: a person who is trying to gain knowledge or skill in something by studying, practicing, or being taught(M-W Learner's, similar to technical Fr.)
There's the level of skill, the process of learning, the designation, the time, the age, the focus, the place where the learning occurs. There is the learner's permit; it is something temporary, a transient state with a foreseeable end. On the other hand with other types of skills, from a process point of view, not all beginners are learners, and conversely not all learners are beginners.
Is the "learner" mainly a student? A beginner? What is the difference? Is there a technical meaning which is different from the casual meaning? Does it make sense to use intermediate/adult with learner i.e. an adult intermediate learner etc.?