1) persons without a payed job: - unemployed: persons who have recently looked for work or are available for work at a short notice; - semi unemployed: persons who have looked for work recently, but are not available at short term or vice versa. 2) persons with a payed job: - part-time employed: persons who are working part-time and are available at short notice.
Eurostat speaks of ‘labour market slack’. The International Labour Organization (ILO) calls it ‘labour underutilization’. Both organizations also use terms like: ‘unmet demand / need for employment’. Semi-unemployed are named by Eurostat as ‘potential additional labour force’ by ILO as ‘potential labour force’.