1) Not utilized fully 2) Part-time 
[adj] - employed only part-time when one needs full-time employment or not making full use of your skills
adjective employed only part-time when one needs full-time employment or not making full use of your skills; `migrants are likely to be poor and underemployed`; `able people are kept underemployed`
employed at a job that does not fully use one's skills or abilities. · employed only part-time when one is available for full-time work. · not utilized fully.