On-the-job (adjective)

1. Of or pertaining to work done while employed at a job.
2. Relating to training or skills acquired while performing a job.
3. Taking place or occurring during the course of one's work.

Origin:

From the phrase 'on the job training', meaning learning while performing a job.

Examples:

1. He learned all his construction skills on-the-job while working for his father's company.
2. The company offers on-the-job training for all new employees.
3. Safety procedures are important to follow while on-the-job.